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Sample records for floating knee epidemiology

  1. Management of the Floating Knee in Polytrauma Patients

    PubMed Central

    Bertrand, M.L.; Andrés-Cano, P.

    2015-01-01

    Ipsilateral fracture of the femur and tibia, or floating knee, is a rare injury that is found almost exclusively in polytrauma or high-energy trauma patients. It presents a combination of diaphyseal, metaphyseal and intra-articular fractures of the femur and tibia, with a high incidence of neurovascular, ligamentous and soft-tissue injuries. The functional outcome and, in some cases, the life, of such polytrauma patients depends largely on a correct therapeutic approach being taken. In general, the treatment decided upon will depend on the individual characteristics present, regarding aspects such as the patient’s general condition, the fracture line and the state of the soft tissues. The treatment provided may be the same as when single fractures are presented, but it is often necessary to consider whether certain techniques or surgical approaches may interfere with other lines of treatment. It is essential at all times to take into consideration the associated injuries and complications before deciding upon a treatment strategy. Ligamentous injuries play an important role in these injuries, much more so than when fractures occur singly. Therefore, these injuries require management by an experienced multidisciplinary team. PMID:26312119

  2. Knee Injuries in American Football: An Epidemiological Review.

    PubMed

    Rothenberg, Paul; Grau, Luis; Kaplan, Lee; Baraga, Michael G

    Football has the highest injury rate amongst popular American sports. Of those injuries that end seasons or careers, the knee is the most common culprit. This is of particular concern because knee injuries are most common in football. This article reviews 4 of the most common knee injuries in American football, with emphasis on epidemiology, risk factors, and treatment outcomes. The injuries reviewed are tears of the anterior cruciate ligament, medial collateral ligament, medial patellofemoral ligament, and posterior cruciate ligament.

  3. Traumatic Extra-capsular and Intra-capsular Floating Fat: Fat-fluid Levels of the Knee Revisited

    PubMed Central

    Davis, Derik L; Vachhani, Prasann

    2015-01-01

    Floating fat is a sign of acute bone injury at the knee following trauma. The goal of this article is to review the etiology, patterns, and mimickers of extra-capsular and intra-capsular floating fat, with the major emphasis on knee trauma in the acute setting. We will discuss the spectrum of multimodal imaging findings for rare presentations of extra-capsular floating fat, and contrast these with common and atypical forms of intra-capsular lipohemarthrosis, as an aid to the assessment of acute bone trauma at the knee. PMID:26713176

  4. Effect of floating toes on knee and trunk acceleration during walking: a preliminary study

    PubMed Central

    Uritani, Daisuke; Sakamoto, Chinatsu; Fukumoto, Takahiko

    2017-01-01

    [Purpose] This study investigated the effect of floating toes on knee and trunk acceleration during walking in experimental setting. [Subjects and Methods] Twelve healthy volunteers walked barefoot at a preferred speed along a linear pathway under 2 conditions: normal gait (control) condition and floating toes (FT) condition. In the latter, weight bearing by the toes was avoided using kinesiology tape applied along the toe extensors. Accelerations of the knee (Kn) and lumbar spine (Lx) were assessed using triaxial accelerometers mounted on the right fibular head and the spinous process of L3. Acceleration vectors were oriented such that the anterior, right, and cranial deviations were positive along the anteroposterior, lateral, and vertical axes, respectively. The root mean squares (RMSs; anteroposterior, RMSap; lateral, RMSl; vertical, RMSv) were calculated, and the mean values of 3 trials in each condition were determined. Differences between the conditions were assessed using the Wilcoxon signed-rank test. [Results] LxRMSap and LxRMSv were larger in the FT condition than in the control condition. KnRMSv tended to be higher in the FT condition than in the control condition. [Conclusion] Floating toes increase acceleration and might create mechanical stress on the lower back and knee during walking. PMID:28265174

  5. Influence of gap balance on the sagittal movement of a specific mobile bearing floating platform design in total knee arthroplasty.

    PubMed

    Lee, Dae-Hee; Lee, Dong-Ki; Shin, Young-Soo; Han, Seung-Beom

    2013-12-01

    We analyzed 119 knees implanted with mobile bearing floating platform prostheses using the navigation-assisted gap balancing technique to analyze the relationship between intraoperative sagittal movement of floating platforms and soft tissue balancing. The 95 (79.8%) knees were classified into the positive rollback group (mean insert posterior rollback 5.86 ± 1.24 mm), and the remaining 24 (20.2%) into the negative rollback group. Lateral flexion gap (LFG) differed significantly between knees with positive and negative rollback (20.5 ± 1.7 mm vs 22.1 ± 1.7 mm, P = .021). Only LFG significantly influenced the occurrence of bearing sagittal movement. Sagittal translation of the insert occurred in about 80% of knees implanted with mobile bearing floating platforms in TKA, and was affected by flexion gaps, especially on the lateral side.

  6. Traumatic Floating Knee: A Review of a Multi-Centric Series of 172 Cases in Adult

    PubMed Central

    Feron, J.-M.; Bonnevialle, P.; Pietu, G.; Jacquot1, F.

    2015-01-01

    The traumatic floating knee in adults (FK) is a combined injury of the lower limb defined by ipsilateral fractures of the tibia and femur. The first publications emphasized the severity of injuries, the bad results after conservative treatment, the most severe functional outcome in case of articular fracture and the frequency of associated cruciate ligament injuries. The surgical management of FK has been highly modified according the improvement of the fracture fixation devices and the operative techniques. This retrospective multicentric observational study included 172 adults with a FK injury admitted in emergency in 5 different level I or II trauma centers. All the patients data were collected on an anonymized database. Results were evaluated by the overall clinical Karlström’s score at latest follow-up. Fracture union was assessed on X-rays when at least 3 out of 4 cortices were in continuity in two different radiological planes. A statistical analysis was performed by a logistic regression method. Despite some limitations, this study confirms the general and local severity of this high-energy trauma, mainly occurring in young people around the third decade. A special effort should lead to a better initial diagnosis of associated ligamentous injury: a tear of PCL can be suspected on a lateral-ray view and a testing of the knee should be systematically performed after fixation of the fracture under anesthesia. Secondary MRI assessment is sometimes difficult to interpret because of hardware artifacts. The timing of fracture fixation is discussed on a case by case basis. However, a first femoral fixation is recommended except in cases of tibia fracture with major soft tissue lesion or leg ischemia requiring the tibia fixation first. Also a tibia stabilized facilitates the reduction and fixation of a complex distal femur fracture. The dual nailing remains so far for us the best treatment in Fraser I FK. Further prospective studies are needed to validate

  7. Epidemiology and Impact of Knee Injuries in Major and Minor League Baseball Players.

    PubMed

    Dahm, Diane L; Curriero, Frank C; Camp, Christopher L; Brophy, Robert H; Leo, Tony; Meister, Keith; Paletta, George A; Steubs, John A; Mandelbaum, Bert R; Pollack, Keshia M

    2016-01-01

    Few studies have explored the frequency and impact of lower extremity injuries, such as those to the knee, among professional baseball players. The purpose of this study was to detail the epidemiology of knee injuries in Major League Baseball (MLB) and Minor League Baseball (MiLB) players during the 2011-2014 seasons. It was hypothesized that knee injuries are a common occurrence in these athletes, and represent a significant source of time away from play. The MLB Health and Injury Tracking System database was searched to identify all patients diagnosed with knee injuries during the 2011-2014 seasons. All injuries that occurred during the preseason, regular season, and postseason that resulted in time away from play were included. Injury data analyzed included total number of knee injuries, specific diagnoses, injury mechanisms, locations, player positions, and time lost. Descriptive statistics were conducted and injury rates per athlete-exposures were calculated. During the 2011-2014 seasons, a total of 2171 knee injuries occurred in MLB and MiLB players, representing 6.5% of all injuries in professional baseball. The knee injury rate across both the MLB and MiLB was 1.2 per 1000 athlete-exposures. The mean number of days missed per injury across both leagues was 16.2 with a total of 30,449 days of missed play amongst all athletes over the 4 seasons. Injuries to the knee were the fifth most common cause of missed time in all of baseball, and the fourth most common reason for missed games in the MLB alone. Approximately 12% of all injuries required surgical intervention. The most common mechanism of injury was noncontact (44%), and base runners were injured more frequently than any other position (24%). The infield (30%) and home plate (23%) were the most common locations in which injuries occurred. These data can be utilized for targeted injury prevention initiatives.

  8. Mid-term outcomes of floating platform mobile-bearing total knee arthroplasty under navigational guidance with a minimum 4-year follow-up.

    PubMed

    Lee, Dae-Hee; Lee, Dong-Ki; Shin, Young-Soo; Han, Seung-Beom

    2013-12-01

    We evaluated 106 knees that underwent primary total knee arthroplasty (TKA) with the navigation-assisted gap balancing technique using an e.-motion cruciate retaining floating platform (FP) mobile-bearing prosthesis to prospectively assess the survival of the e.-motion FP system after a minimum follow-up of 4 years. There was no evidence of any complications, including dissociation or breakage of the polyethylene liner or component loosening at last follow up (5.1 ± 0.6 years). Four knees, however, required re-operation, three for distal femoral fracture, and one for infection. The estimated 5-year prosthesis survival rates without revision for any reason and for prosthesis-associated problems were 96.2% and 100%, respectively. The e.-motion floating platform, with a cruciate retaining design under navigation guidance, demonstrated excellent clinical results and 5-year survival rate.

  9. EPIDEMIOLOGICAL STUDY ON TENDON RUPTURES OF THE KNEE EXTENSOR MECHANISM AT A LEVEL 1 HOSPITAL

    PubMed Central

    Pires e Albuquerque, Rodrigo; Prado, Juliano; Hara, Rafael; Ferreira, Evaldo; Schiavo, Leonardo; Giordano, Vincenzo; Amaral, Ney Pecegueiro do; Barretto, João Mauricio

    2015-01-01

    Objectives: The purpose of the present study was to review the epidemiological aspects of tendon ruptures of the knee extensor apparatus at a level 1 hospital. Methods: We retrospectively analyzed 76 lesions of the knee extensor apparatus that were treated surgically at the Miguel Couto Municipal Hospital between March 2004 and March 2011. We took into consideration age, sex, trauma mechanism, anatomical classification of the lesion, affected side, comorbidities and associated lesions. Results: Among the patients studied, 68 were male and the mean age was 36 years. Regarding the trauma mechanism, 62 lesions occurred due to direct trauma; the right side was affected in 21 cases; eight presented comorbidities and four presented associated lesions. Conclusion: The majority of the patients were male, at an economically active age (young people), and were victims of direct trauma. Ruptures of the patellar ligament were the most frequent lesions. Associated lesions were rare and comorbidities were infrequent in our sample. PMID:27047890

  10. Reliability and Validity of the Anterior Knee Pain Scale: Applications for Use as an Epidemiologic Screener

    PubMed Central

    2016-01-01

    A screening instrument’s ability to provide clinicians with consistent and reproducible information is crucial to intervention. Despite widespread acceptance and clinical use of the Kujala Anterior Knee Pain Scale (AKPS) in orthopedics and sports medicine, few studies have reported on its reliability and no such studies have concentrated on child or adolescent samples exclusively, segments of the population for which this instrument is often used. The purpose of the current study was to describe and report on the reliability and validity of the AKPS for use with high school female athletes participating in interscholastic athletics. The study was a secondary analysis of prospective epidemiologic data using established scale validation methods. The records of 414 female athletes 11.0 to 18.1 years of age (Mean 13.9 yrs, SD = 1.7 yrs) were used for analysis. Four different approaches to scoring and scale reduction of the AKPS were evaluated, including the original, ordinal 13-item form, a modified, ordinal 6-item form, a modified, dichotomous 13-item form, and a modified, dichotomous 6-item form. Three different types of reliability (internal consistency, equivalence across forms, standard error of measurement) and one type of validity (criterion-related) were estimated for the AKPS in the current sample. The four scoring formats of the AKPS scale were found to have high internal consistency (αcoef = 0.83 to 0.91), equivalence across the short and long forms (r = 0.98), acceptable standard errors of measurement (0.82 to 3.00), and moderate to high criterion related validity—as determined by physican’s diagnosis: 0.92 (13-item form), 0.90 (6-item form). The Kujala AKPS is a valid and reliable measure of anterior knee pain and appropriate for use as an epidemiologic screening tool with adolescent female athletes. PMID:27441381

  11. Prospective Epidemiological Study of Basketball Injuries During One Competitive Season: Ankle Sprains and Overuse Knee Injuries

    PubMed Central

    Cumps, Elke; Verhagen, Evert; Meeusen, Romain

    2007-01-01

    This prospective cohort study aims to assess the overall incidence of acute and overuse basketball injuries and identifies risk factors associated with ankle sprains and knee overuse injuries. In total, 164 senior players (23.7 years ± 7.0) of all levels of play, and including both men and women, participated voluntarily during one season. A total of 139 acute and 87 overuse injuries were reported, resulting in an overall injury incidence of 9.8 (8.5 to 11.1) per 1,000 hours. The incidence of acute injuries was 6.0/1,000 hours. Ankle sprains (n = 34) accounted for most acute injuries, and 52.9% of all players with ankle sprains reported a previous ankle sprain. Relative Risks (RR) and Odds Ratio (OR) with their 95% Confidence Intervals (CI) were calculated to determine significant differences. Landing on an opponent’s foot was the major inciting event, significantly more so than non contact mechanisms (RR=2.1 [95% CI: 1.0-4.2]). Acute knee injuries resulted in the highest playing absence (7 weeks 2 days ± 9 weeks 1 day). Overuse injury incidence was 3.8/1,000 hours. The knee (1.5/1,000 hours) was the most common site. Forward players sustained less knee overuse injuries than players of all other playing positions, and significantly less than center players (OR=0.5 [95% CI: 0.2-0.9]). This study showed that ankle sprains and overuse knee injuries are the most common injuries in basketball, both accounting for 14.8%. Injury prevention programmes however should not concentrate on those injuries only, but might one to consider that acute knee injuries, in spite of the fact that they occur less frequently, also merit further research. Key pointsAnkle sprains are the most common acute injuries in basketball with the inciting event being landing on an opponent’s foot or changing direction.Anterior knee pain is the most common overuse injury. Etiologic factors are well described in literature, but prevention strategies are lacking.Acute knee injuries account for the

  12. Floating patella associated with lymphoedema

    PubMed Central

    Vun, Shen Hwa; Bayam, Levent; Drampalos, Efstathios; Jesry, Mohammed; Fadel, George

    2015-01-01

    Ipsilateral injury of more than one component of the knee extensor apparatus is rare. It is mostly associated with previous trauma, surgery, immunosuppression therapy and systemic disease. We present the first documented case of a spontaneous bifocal disruption of the knee extensor apparatus (i.e. floating patella) associated with lymphoedema. This case highlights the importance of considering lymphoedema as another risk factor for rupture of the knee extensor apparatus. It also highlights the importance of assessing all components of the knee extensor apparatus in patients presenting with acute knee injuries. PMID:25802253

  13. Reimplantation of contaminated extruded segment of lateral femoral condyle cleansed with 10% povidine-iodine in complex floating knee injury with excellent outcome: Case report with 2 year follow up.

    PubMed

    Singhi, Prahalad Kumar; Sivakumar, R; Somashekar, V; Kusabi, Vinayak; Vinoth, T

    2016-01-01

    Traumatic extrusion of bone is a rare complication of high energy open fractures, and there are only few studies published in literature on reimplantation of the extruded bone segment. Studies with clear guidelines regarding timing of reimplantation, stabilisation of extruded bone segments, bone disinfection and disinfection techniques are very few. Previous reports describe disinfection using thermal or chemical methods. We present a case scenario of successful reimplantation of an extruded metaphyseal segment of distal femoral condyle following cleaning with copious saline and soaked in 10% povidine-iodine for 20 min in a 21 year old male patient of a complex floating knee injury with excellent outcome based on Karlstrom and Olerud criteria.

  14. Runner's Knee

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Runner's Knee KidsHealth > For Teens > Runner's Knee A A A ... told he had runner's knee. What Is Runner's Knee? Runner's knee is the term doctors use for ...

  15. Knee pain

    MedlinePlus

    Pain - knee ... Knee pain can have different causes. Being overweight puts you at greater risk for knee problems. Overusing your knee can trigger knee problems that cause pain. If you have a history of arthritis, it ...

  16. Stools - floating

    MedlinePlus

    ... absorption of nutrients ( malabsorption ) or too much gas (flatulence). Considerations Most causes of floating stools are harmless. ... Elsevier Saunders; 2016:chap 140. Read More Gas - flatulence Malabsorption Review Date 5/11/2016 Updated by: ...

  17. On floats and float tests

    NASA Technical Reports Server (NTRS)

    Seewald, Friedrich

    1931-01-01

    The principal source of information on float resistance is the model test. In view of the insuperable difficulties opposing any attempt at theoretical treatment of the resistance problem, particularly at attitudes which tend toward satisfactory take-off, such as the transitory stage to planing, the towing test is and will remain the primary method for some time.

  18. An expert-based job exposure matrix for large scale epidemiologic studies of primary hip and knee osteoarthritis: The Lower Body JEM

    PubMed Central

    2014-01-01

    Background When conducting large scale epidemiologic studies, it is a challenge to obtain quantitative exposure estimates, which do not rely on self-report where estimates may be influenced by symptoms and knowledge of disease status. In this study we developed a job exposure matrix (JEM) for use in population studies of the work-relatedness of hip and knee osteoarthritis. Methods Based on all 2227 occupational titles in the Danish version of the International Standard Classification of Occupations (D-ISCO 88), we constructed 121 job groups comprising occupational titles with expected homogeneous exposure patterns in addition to a minimally exposed job group, which was not included in the JEM. The job groups were allocated the mean value of five experts’ ratings of daily duration (hours/day) of standing/walking, kneeling/squatting, and whole-body vibration as well as total load lifted (kg/day), and frequency of lifting loads weighing ≥20 kg (times/day). Weighted kappa statistics were used to evaluate inter-rater agreement on rankings of the job groups for four of these exposures (whole-body vibration could not be evaluated due to few exposed job groups). Two external experts checked the face validity of the rankings of the mean values. Results A JEM was constructed and English ISCO codes were provided where possible. The experts’ ratings showed fair to moderate agreement with respect to rankings of the job groups (mean weighted kappa values between 0.36 and 0.49). The external experts agreed on 586 of the 605 rankings. Conclusion The Lower Body JEM based on experts’ ratings was established. Experts agreed on rankings of the job groups, and rankings based on mean values were in accordance with the opinion of external experts. PMID:24927760

  19. [Physical activity for knee osteoarthritis.

    PubMed

    Nagao, Masashi; Ishijima, Muneaki; Kaneko, Haruka; Takazawa, Yuji; Ikeda, Hiroshi; Kaneko, Kazuo

    Elder populations have been increasing in Japan and estimated 24 million people have knee osteoarthritis(OA). Recently, people have diverse sociological background and demand for participating sports has been growing. People may participate sports to prevent some diseases such as locomotive syndrome. According to the recent studies, excessive high impact sports increase the risk of OA, while daily life exercise decrease the risk. Epidemiological approach demonstrated that reduced knee extension muscle strength increases the risk of OA. We reviewed and discussed the recent topics including efficacy of physical therapy for knee OA and how much sports activities could be beneficial after knee surgery.

  20. Knee Bursitis

    MedlinePlus

    ... make a diagnosis of knee bursitis during a physical exam. Your doctor will inspect your knee by: Comparing the condition of both knees, particularly if only one is painful Gently pressing on different areas of your knee to detect warmth, swelling and the source of pain Carefully moving ...

  1. Knee pain, knee injury, knee osteoarthritis & work.

    PubMed

    Dulay, Gurdeep S; Cooper, C; Dennison, E M

    2015-06-01

    Symptomatic knee osteoarthritis (OA) can be viewed as the end result of a molecular cascade which ensues after certain triggers occur and ultimately results in irreversible damage to the articular cartilage. The clinical phenotype that knee OA can produce is variable and often difficult to accurately predict. This is further complicated by the often poor relationship between radiographic OA and knee pain. As a consequence, it can be difficult to compare studies that use different definitions of OA. However, the literature suggests that while there are multiple causes of knee OA, two have attracted particular attention over recent years; occupation related knee OA and OA subsequent to previous knee injury. The evidence of a relationship, and the strength of this association, is discussed in this chapter.

  2. Obesity and osteoarthritis in knee, hip and/or hand: An epidemiological study in the general population with 10 years follow-up

    PubMed Central

    Grotle, Margreth; Hagen, Kare B; Natvig, Bard; Dahl, Fredrik A; Kvien, Tore K

    2008-01-01

    Background Obesity is one of the most important risk factors for osteoarthritis (OA) in knee(s). However, the relationship between obesity and OA in hand(s) and hip(s) remains controversial and needs further investigation. The purpose of this study was to investigate the impact of obesity on incident osteoarthritis (OA) in hip, knee, and hand in a general population followed in 10 years. Methods A total of 1854 people aged 24–76 years in 1994 participated in a Norwegian study on musculoskeletal pain in both 1994 and 2004. Participants with OA or rheumatoid arthritis in 1994 and those above 74 years in 1994 were excluded, leaving n = 1675 for the analyses. The main outcome measure was OA diagnosis at follow-up based on self-report. Obesity was defined by a body mass index (BMI) of 30 and above. Results At 10-years follow-up the incidence rates were 5.8% (CI 4.3–7.3) for hip OA, 7.3% (CI 5.7–9.0) for knee OA, and 5.6% (CI 4.2–7.1) for hand OA. When adjusting for age, gender, work status and leisure time activities, a high BMI (> 30) was significantly associated with knee OA (OR 2.81; 95%CI 1.32–5.96), and a dose-response relationship was found for this association. Obesity was also significantly associated with hand OA (OR 2.59; 1.08–6.19), but not with hip OA (OR 1.11; 0.41–2.97). There was no statistically significant interaction effect between BMI and gender, age or any of the other confounding variables. Conclusion A high BMI was significantly associated with knee OA and hand OA, but not with hip OA. PMID:18831740

  3. Prophylactic Knee Braces: Where Do They Stand?

    ERIC Educational Resources Information Center

    McCarthy, Paul

    1988-01-01

    The effectiveness of knee braces in preventing knee injuries in football is inconclusive. This article reviews research from epidemiologic, cadaver, and surrogate studies; discusses reasons for conflicting study results, including research design problems; and describes alternative approaches that have been suggested. (IAH)

  4. "Floating shoulder" injuries.

    PubMed

    Heng, Kenneth

    2016-12-01

    "Floating shoulder" is a rare injury complex resulting from high-energy blunt force trauma to the shoulder, resulting in scapulothoracic dissociation. It is commonly associated with catastrophic neurovascular injury. Two cases of motorcyclists with floating shoulder injuries are described.

  5. WindWaveFloat

    SciTech Connect

    Weinstein, Alla

    2011-11-01

    Presentation from the 2011 Water Peer Review includes in which principal investigator Alla Weinstein discusses project progress in development of a floating offshore wind structure - the WindFloat - and incorporation therin of a Spherical Wave Energy Device.

  6. Floating: sink or swim.

    PubMed

    Pronger, L

    1995-12-01

    Budget restrictions, fewer human resources and fluctuating patient populations have combined to increase the practice of floating general duty nurses. Floating occurs when a nurse from an overstaffed unit, based on patient load, is required to work in another unit that is understaffed. Floating is not a new practice, but it has always been an emotionally charged issue. Today, with more float pool nurses seeking the security of a permanent position in a home unit, the issue has increased in intensity.

  7. The Design of Floats

    NASA Technical Reports Server (NTRS)

    Sottorf, W

    1938-01-01

    Following a summary of the multiplicity of domestic and foreign floats and a brief enumeration of the requirements of floats, the essential form parameters and their effect on the qualities of floats are detailed. On this basis a standard float design is developed which in model families with varying length/beam ratio and angle of dead rise is analyzed by an experimental method which permits its best utilization on any airplane.

  8. Jumper's Knee (Patellar Tendonitis)

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Jumper's Knee KidsHealth > For Teens > Jumper's Knee A A A ... continued damage to the knee. How Does the Knee Work? To understand how jumper's knee happens, it ...

  9. Knee arthroscopy - series (image)

    MedlinePlus

    ... knee problems such as: a torn knee disc (meniscus) a damaged knee bone (patella) a damaged ligament ... surgeon can see the ligaments, the knee disc (meniscus), the knee bone (patella), the lining of the ...

  10. Runner's Knee

    MedlinePlus

    ... name just two. It's the most common overuse injury among runners, but it can also strike other athletes who do activities that require a lot of knee bending, such as biking, jumping, or skiing. Runner's knee happens when the kneecap (patella) tracks incorrectly over a ...

  11. Knee Injuries

    MedlinePlus

    ... keeping it from bending outward. anterior cruciate ligament (ACL): The ACL connects your femur to your tibia at the ... Common knee sprains usually involve damage to the ACL and/or MCL. The most serious sprains involve ...

  12. Knee MRI

    MedlinePlus

    ... of the knee uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ...

  13. Knee Dislocations

    PubMed Central

    Schenck, Robert C.; Richter, Dustin L.; Wascher, Daniel C.

    2014-01-01

    Background: Traumatic knee dislocation is becoming more prevalent because of improved recognition and increased exposure to high-energy trauma, but long-term results are lacking. Purpose: To present 2 cases with minimum 20-year follow-up and a review of the literature to illustrate some of the fundamental principles in the management of the dislocated knee. Study Design: Review and case reports. Methods: Two patients with knee dislocations who underwent multiligamentous knee reconstruction were reviewed, with a minimum 20-year follow-up. These patients were brought back for a clinical evaluation using both subjective and objective measures. Subjective measures include the following scales: Lysholm, Tegner activity, visual analog scale (VAS), Short Form–36 (SF-36), International Knee Documentation Committee (IKDC), and a psychosocial questionnaire. Objective measures included ligamentous examination, radiographic evaluation (including Telos stress radiographs), and physical therapy assessment of function and stability. Results: The mean follow-up was 22 years. One patient had a vascular injury requiring repair prior to ligament reconstruction. The average assessment scores were as follows: SF-36 physical health, 52; SF-36 mental health, 59; Lysholm, 92; IKDC, 86.5; VAS involved, 10.5 mm; and VAS uninvolved, 2.5 mm. Both patients had excellent stability and were functioning at high levels of activity for their age (eg, hiking, skydiving). Both patients had radiographic signs of arthritis, which lowered 1 subject’s IKDC score to “C.” Conclusion: Knee dislocations have rare long-term excellent results, and most intermediate-term studies show fair to good functional results. By following fundamental principles in the management of a dislocated knee, patients can be given the opportunity to function at high levels. Hopefully, continued advances in the evaluation and treatment of knee dislocations will improve the long-term outcomes for these patients in the

  14. Float Zone Workshop

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.

    1980-01-01

    A summary of the Analytical Float Zone Experiment System (AFZES) concept is presented. The types of experiments considered for such a facility are discussed. Reports from various industrial producers and users of float zone material are presented. Special emphasis is placed on state-of-the-art developments in low gravity manufacturing and their applications to space processing.

  15. Floating emitter solar cell

    NASA Technical Reports Server (NTRS)

    Chih, Sah (Inventor); Cheng, Li-Jen (Inventor)

    1987-01-01

    A front surface contact floating emitter solar cell transistor is provided in a semiconductor body (n-type), in which floating emitter sections (p-type) are diffused or implanted in the front surface. Between the emitter sections, a further section is diffused or implanted in the front surface, but isolated from the floating emitter sections, for use either as a base contact to the n-type semiconductor body, in which case the section is doped n+, or as a collector for the adjacent emitter sections.

  16. Micromechanisms with floating pivot

    DOEpatents

    Garcia, Ernest J.

    2001-03-06

    A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use floating pivot structures to relieve some of the problems encountered in the use of solid flexible pivots.

  17. Reducing float coal dust

    PubMed Central

    Patts, J.R.; Colinet, J.F.; Janisko, S.J.; Barone, T.L.; Patts, L.D.

    2016-01-01

    Controlling float coal dust in underground coal mines before dispersal into the general airstream can reduce the risk of mine explosions while potentially achieving a more effective and efficient use of rock dust. A prototype flooded-bed scrubber was evaluated for float coal dust control in the return of a continuous miner section. The scrubber was installed inline between the face ventilation tubing and an exhausting auxiliary fan. Airborne and deposited dust mass measurements were collected over three days at set distances from the fan exhaust to assess changes in float coal dust levels in the return due to operation of the scrubber. Mass-based measurements were collected on a per-cut basis and normalized on the basis of per ton mined by the continuous miner. The results show that average float coal dust levels measured under baseline conditions were reduced by more than 90 percent when operating the scrubber. PMID:28018004

  18. Floating Magnet Demonstration.

    ERIC Educational Resources Information Center

    Wake, Masayoshi

    1990-01-01

    A room-temperature demonstration of a floating magnet using a high-temperature superconductor is described. The setup and operation of the apparatus are described. The technical details of the effect are discussed. (CW)

  19. Stabilized floating platforms

    DOEpatents

    Thomas, David G.

    1976-01-01

    The subject invention is directed to a floating platform for supporting nuclear reactors and the like at selected offshore sites. The platform is provided with a stabilizer mechanism which significantly reduces the effects of wave action upon the platform and which comprises a pair of relatively small floats attached by rigid booms to the platform at locations spaced therefrom for reducing wave pitch, acceleration, and the resonance period of the wave.

  20. Knee Menisci.

    PubMed

    Bryceland, James Kevin; Powell, Andrew John; Nunn, Thomas

    2017-04-01

    The menisci of the knees are semicircular fibrocartilaginous structures consisting of a hydrophilic extracellular matrix containing a network of collagen fibers, glycoproteins, and proteoglycans maintained by a cellular component. The menisci are responsible for more than 50% of load transmission across the knee and increase joint congruity thereby also aiding in fluid film lubrication of the joint. In the United Kingdom, meniscal tears are the most common form of intra-articular knee injury and one of the commonest indications for orthopedic intervention. The management of these injuries is dependent on the location within the meniscus (relative to peripheral blood supply) and the pattern of tear. Removal of meniscus is known to place the knee at increased risk of osteoarthritis; therefore repair of meniscal tears is preferable. However, a significant proportion of tears are irreparable and can only be treated by partial or even complete meniscectomy. More recent studies have shown encouraging results with meniscal replacement in this situation, though further work is required in this area.

  1. Recent Advances and Developments in Knee Surgery: Principles of Periprosthetic Knee Fracture Management

    PubMed Central

    Chimutengwende-Gordon, Mukai; Khan, Wasim; Johnstone, David

    2012-01-01

    The management of distal femoral, tibial and patellar fractures after total knee arthroplasty can be complex. The incidence of these fractures is increasing as the number of total knee arthroplasties being performed and patient longevity is increasing. There is a wide range of treatment options including revision arthroplasty for loose implants. This review article discusses the epidemiology, risk factors, classification and treatment of these fractures. PMID:22888380

  2. Knee CT scan

    MedlinePlus

    CAT scan - knee; Computed axial tomography scan - knee; Computed tomography scan - knee ... scanners can perform the exam without stopping.) A computer makes several images of the body area. These ...

  3. Knee pain (image)

    MedlinePlus

    ... front of the knee can be due to bursitis, arthritis, or softening of the patella cartilage as ... knee. Overall knee pain can be due to bursitis, arthritis, tears in the ligaments, osteoarthritis of the ...

  4. Total Knee Replacement

    MedlinePlus

    ... stability. The long thigh muscles give the knee strength. All remaining surfaces of the knee are covered ... physical examination. This will assess knee motion, stability, strength, and overall leg alignment. • X-rays. These images ...

  5. Knee joint replacement

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002974.htm Knee joint replacement To use the sharing features on this page, please enable JavaScript. Knee joint replacement is a surgery to replace a knee ...

  6. Water on the Knee

    MedlinePlus

    ... your knee joint. Some people call this condition "water on the knee." A swollen knee may be ... Choose low-impact exercise. Certain activities, such as water aerobics and swimming, don't place continuous weight- ...

  7. Floating Versus Sinking

    NASA Astrophysics Data System (ADS)

    Vella, Dominic

    2015-01-01

    Small objects that are more dense than water may still float at the air-water interface because of surface tension. Whether this is possible depends not only on the density and size of the object, but also on its shape and surface properties, whether other objects are nearby, and how gently the object is placed at the interface. This review surveys recent work to quantify when objects can float and when they must sink. Much interest in this area has been driven by studies of the adaptations of water-walking insects to life at interfaces. I therefore discuss these results in the context of this and other applications.

  8. Tethered float liquid level sensor

    DOEpatents

    Daily, III, William Dean

    2016-09-06

    An apparatus for sensing the level of a liquid includes a float, a tether attached to the float, a pulley attached to the tether, a rotation sensor connected to the pulley that senses vertical movement of said float and senses the level of the liquid.

  9. Floated gravity gradiometer and method

    SciTech Connect

    Lautzenhiser, T.V.; Eisner, M.

    1990-09-11

    This patent describes a gravity gradiometer. It comprises: a housing containing a fluid; a float buoyantly supported within the fluid; means for varying the metacentric height of the float; and means for obtaining a measure of the gravitational gradient acting on the float resulting from varying the metacentric height.

  10. Compound floating pivot micromechanisms

    DOEpatents

    Garcia, Ernest J.

    2001-04-24

    A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use compound floating pivot structures to attain far greater tilt angles than are practical using other micromechanical techniques. The new mechanisms are also capable of bi-directional tilt about multiple axes.

  11. Why Do Things Float?

    ERIC Educational Resources Information Center

    Selley, Nicholas

    1993-01-01

    Combines two strands: one being an exposition of the variety of explanations which are given for the phenomenon of floating; the other being the pedagogical implications which arise from the use of alternative models in science. Attention is drawn to the ethical questions that may arise when primary science seems to conflict with accepted…

  12. Knee Injuries and Disorders

    MedlinePlus

    Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt ... your life. The most common disease affecting the knee is osteoarthritis. The cartilage in the knee gradually wears away, ...

  13. [Chronic knee joint discomfort].

    PubMed

    Wittke, R

    2005-06-23

    Chronic pain in the knee joint is frequently a sign of arthrosis in adults. This must be clearly differentiated from other knee problems. Patellofemoral stress syndrome (occurs mostly in young people) and arthritis with effusion in the knee joint after long and mostly unusual stress also allow only a reduced function of the knee joint. However, even when the knee joint is still fully functional, chronic problems could already exist: For example, for joggers, iliotibial band friction syndrome (runner's knee) or after high unphysiological stress, patellar tendinopathy (jumper's knee). These must be differentiated from pes anserinus syndrome and a plica mediopatellaris.

  14. FLOPAK: FLOATING POINT PROGRAMING PACKAGE,

    DTIC Science & Technology

    FLOPAK is a Packard-Bell 250 Computer semi-automatic, floating - point programing system which may be operated simultaneously in either of two modes...250 floating - point system available which may be used in real-time control. The system was originally designed to solve a real-time communication problem....The first is a non-time optimized mode which may be used by inex perienced coders; the second mode is a high-speed, fully time-optimized floating

  15. Genetics Home Reference: Floating-Harbor syndrome

    MedlinePlus

    ... Understand Genetics Home Health Conditions Floating-Harbor syndrome Floating-Harbor syndrome Enable Javascript to view the expand/ ... boxes. Download PDF Open All Close All Description Floating-Harbor syndrome is a disorder involving short stature, ...

  16. Floating-diffusion electrometer with adjustable sensitivity

    NASA Technical Reports Server (NTRS)

    Tower, John R. (Inventor)

    1989-01-01

    The effective capacitance of the floating diffusion in a floating-diffusion electrometer is modified to adjust electrometer sensitivity. This is done by changing the direct potential applied to a gate electrode proximate to the floating diffusion.

  17. Knee Bracing: What Works?

    MedlinePlus

    ... that make knee braces claim that their products work well. Scientific studies have not completely agreed. It's not clear what the knee braces actually do. Braces often work better in the laboratory than they do in ...

  18. Partial knee replacement - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  19. Preventing Knee Injuries

    MedlinePlus

    ... as a result of a twisting or pivoting motion. This injury may cause susceptibility to repeat injuries and knee instability, and therefore often requires surgery. Occasionally, a twisting or hyperextension force to the knee may result in a tibial ...

  20. Knee arthroscopy - discharge

    MedlinePlus

    ... remove it. Torn or damaged anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) Inflamed or damaged ... surgery Knee pain Meniscal allograft transplantation Patient Instructions ACL reconstruction - discharge Getting your home ready - knee or ...

  1. Microprocessor prosthetic knees.

    PubMed

    Berry, Dale

    2006-02-01

    This article traces the development of microprocessor prosthetic knees from early research in the 1970s to the present. Read about how microprocessor knees work, functional options, patient selection, and the future of this prosthetic.

  2. Knee braces - unloading

    MedlinePlus

    ... in their knees, they are referring to a type of arthritis called osteoarthritis . Osteoarthritis is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions all of ...

  3. Examining the knee joint.

    PubMed

    Monk, Daniel

    2013-04-01

    Appropriate history taking and examination can ensure accurate diagnosis of common knee problems, and rapid and effective interventions or referral to orthopaedic specialists. This article describes the anatomy of the knee joint and discusses relevant history taking, the examination process, special tests and radiology, as well as common knee injuries and their management.

  4. BEST POSSIBLE FLOATING POINT ARITHMETIC.

    DTIC Science & Technology

    The report presents an algorithm for floating point arithmetic, using single-length arithmetic registers, which yields the most accurate...approximation which can be expressed in the given floating point format, the greatest lower bound, or the least upper bound for the result of the operation

  5. Does It Sink or Float?

    ERIC Educational Resources Information Center

    McDonald, Judith Richards

    2012-01-01

    This activity is designed to teach prekindergarten to second grade students about the concept of sink or float through an inquiry activity. Students will use familiar objects to predict and test the properties of sink and float. Background information is offered to teachers to assist them with this activity. This lesson begins with an engaging…

  6. Knee disarticulation after total-knee replacement.

    PubMed

    Lambregts, S A M; Hitters, W M G C

    2002-12-01

    An 89-year-old woman who had a total-knee replacement in the past, underwent a knee disarticulation of the same leg because of an ischaemic foot. Eight (8) months postoperatively the stump is fully weight-bearing and the patient is able to walk safely, using a prosthesis and a walking frame.

  7. Knee Lymphocutaneous Fistula Secondary to Knee Arthroplasty

    PubMed Central

    Pérez-de la Fuente, T.; Sandoval, E.; Alonso-Burgos, A.; García-Pardo, L.; Cárcamo, C.; Caballero, O.

    2014-01-01

    Lower limb lymphorrhea secondary to a surgical procedure is a rare but difficult-to-solve complication. In lower limb, this entity is frequently associated with vascular procedures around the inguinal area. We report on a case of a knee lymphocutaneous fistula secondary to a knee revision arthroplasty. To our knowledge, no previous reports regarding this complication have been published. PMID:25580333

  8. Predicting Knee Osteoarthritis.

    PubMed

    Gardiner, Bruce S; Woodhouse, Francis G; Besier, Thor F; Grodzinsky, Alan J; Lloyd, David G; Zhang, Lihai; Smith, David W

    2016-01-01

    Treatment options for osteoarthritis (OA) beyond pain relief or total knee replacement are very limited. Because of this, attention has shifted to identifying which factors increase the risk of OA in vulnerable populations in order to be able to give recommendations to delay disease onset or to slow disease progression. The gold standard is then to use principles of risk management, first to provide subject-specific estimates of risk and then to find ways of reducing that risk. Population studies of OA risk based on statistical associations do not provide such individually tailored information. Here we argue that mechanistic models of cartilage tissue maintenance and damage coupled to statistical models incorporating model uncertainty, united within the framework of structural reliability analysis, provide an avenue for bridging the disciplines of epidemiology, cell biology, genetics and biomechanics. Such models promise subject-specific OA risk assessment and personalized strategies for mitigating or even avoiding OA. We illustrate the proposed approach with a simple model of cartilage extracellular matrix synthesis and loss regulated by daily physical activity.

  9. Floating Silicon Method

    SciTech Connect

    Kellerman, Peter

    2013-12-21

    The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

  10. Floating into Deep Space

    NASA Astrophysics Data System (ADS)

    La Frenais, R.; Saraceno, T.; Powell, J.

    2014-04-01

    Is it possible for spaceflight to become more sustainable? Artist and architect Tomas Saraceno proposes a long-term artscience research project based on his initial work with solar balloons to join with the efforts of engineers such as John Powell, working on the Airship to Orbit experiments, which describe a three stage process of using airships to fly to a large suborbital "Dark Sky Station' then literally floating into orbit with additional electrical and chemical propulsion. (See: http://www.jpaerospace.com) In his artworks Tomás Saraceno proposes cell-like flying cities as possible architectonic living spaces in direct reference to Buckminster Fuller's Cloud Nine (circa 1960). The fantastic architectural utopia Cloud Nine consists of a freely floating sphere measuring one mile in diameter that offers living space to several autonomous communities encompassing thousands of inhabitants each. The notion of the cloud is essential to the artist's work. The cloud as metaphor stands for artistic intention, for the meaning of territory and border in today's (urban) society, and for exploring possibilities for the sustainable development of the human living environment. In Saraceno's work this environment is not limited to the earth, but is explicitly conceived to reach into outer space. (Biomimetic Constructions- On the works of Tomás Saraceno By Katharina Schlüter) Saraceno is also interested in human factors experiments using his existing constructions as analogue environments for living on Mars and is proposing carry out a series of workshops, experiments and solar balloon launces in White Sands desert in early 2016 in collaboration with the curator Dr Rob La Frenais, the Rubin Center at The University of Texas at El Paso and various scientific partners.

  11. Electrically floating, near vertical incidence, skywave antenna

    SciTech Connect

    Anderson, Allen A.; Kaser, Timothy G.; Tremblay, Paul A.; Mays, Belva L.

    2014-07-08

    An Electrically Floating, Near Vertical Incidence, Skywave (NVIS) Antenna comprising an antenna element, a floating ground element, and a grounding element. At least part of said floating ground element is positioned between said antenna element and said grounding element. The antenna is separated from the floating ground element and the grounding element by one or more electrical insulators. The floating ground element is separated from said antenna and said grounding element by one or more electrical insulators.

  12. NULL convention floating point multiplier.

    PubMed

    Albert, Anitha Juliette; Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation.

  13. Control development for floating wind

    NASA Astrophysics Data System (ADS)

    Savenije, Feike; Peeringa, Johan

    2014-06-01

    Control of a floating wind turbine has proven to be challenging, but essential for lowering the cost of floating wind energy. Topic of a recent joint R&D project by GustoMSC, MARIN and ECN, is the concept design and verification with coupled simulations and model tests of the GustoMSC Tri-Floater. Only using an integral design approach, including mooring and control design, a cost effective system can be obtained. In this project, ECN developed a general floating wind turbine control strategy and applied this in a case study to the GustoMSC Tri-Floater and the OC3Hywind spar, both equipped with the NREL 5MW RWT. The designed controller ensures stable operation, while maintaining proper speed and power regulation. The motions of the floating support are reduced and substantial load reduction has been achieved.

  14. NULL Convention Floating Point Multiplier

    PubMed Central

    Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation. PMID:25879069

  15. Floating orbital molecular dynamics simulations.

    PubMed

    Perlt, Eva; Brüssel, Marc; Kirchner, Barbara

    2014-04-21

    We introduce an alternative ab initio molecular dynamics simulation as a unification of Hartree-Fock molecular dynamics and the floating orbital approach. The general scheme of the floating orbital molecular dynamics method is presented. Moreover, a simple but sophisticated guess for the orbital centers is provided to reduce the number of electronic structure optimization steps at each molecular dynamics step. The conservation of total energy and angular momentum is investigated in order to validate the floating orbital molecular dynamics approach with and without application of the initial guess. Finally, a water monomer and a water dimer are simulated, and the influence of the orbital floating on certain properties like the dipole moment is investigated.

  16. Skylab floating ice experiment

    NASA Technical Reports Server (NTRS)

    Campbell, W. J. (Principal Investigator); Ramseier, R. O.; Weaver, R. J.; Weeks, W. F.

    1975-01-01

    The author has identified the following significant results. Coupling of the aircraft data with the ground truth observations proved to be highly successful with interesting results being obtained with IR and SLAR passive microwave techniques, and standard photography. Of particular interest were the results of the PMIS system which operated at 10.69 GHz with both vertical and horizontal polarizations. This was the first time that dual polarized images were obtained from floating ice. In both sea and lake ice, it was possible to distinguish a wide variety of thin ice types because of their large differences in brightness temperatures. It was found that the higher brightness temperature was invariably obtained in the vertically polarized mode, and as the age of the ice increases the brightness temperature increases in both polarizations. Associated with this change in age, the difference in temperature was observed as the different polarizations decreased. It appears that the horizontally polarized data is the most sensitive to variations in ice type for both fresh water and sea ice. The study also showed the great amount of information on ice surface roughness and deformation patterns that can be obtained from X-band SLAR observations.

  17. Floating wind turbine system

    NASA Technical Reports Server (NTRS)

    Viterna, Larry A. (Inventor)

    2009-01-01

    A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips. This large clearance facilitates the use of articulated rotor hubs to reduced damaging structural dynamic loads. Major components of the turbine can be assembled at the shore and transported to an offshore installation site.

  18. Floating into Thin Air

    SciTech Connect

    Hazi, A U

    2007-02-06

    On May 18, 2005, a giant helium balloon carrying the High Energy Focusing Telescope (HEFT) sailed into the spring sky over the deserts of New Mexico. The spindly steel and aluminum gondola that houses the optics, detectors, and other components of the telescope floated for 25 hours after its launch from Fort Sumner, New Mexico. For 21 of those hours, the balloon was nearly 40 kilometers above Earth's surface--almost four times higher than the altitude routinely flown by commercial jet aircraft. In the upper reaches of Earth's atmosphere, HEFT searched the universe for x-ray sources from highly energetic objects such as binary stars, galaxy clusters, and supermassive black holes. Before landing in Arizona, the telescope observed and imaged a dozen scientific targets by capturing photons emitted from these objects in the high-energy (hard) x-ray range (above 10 kiloelectronvolts). Among these targets were the Crab synchrotron nebula, the black hole Cygnus X-1 (one of the brightest x-ray sources in the sky), and the blazar 3C454.3. The scientific data gathered from these targets are among the first focused hard x-ray images returned from high altitudes.

  19. Patterns of knee osteoarthritis in Arabian and American knees.

    PubMed

    Hodge, W Andrew; Harman, Melinda K; Banks, Scott A

    2009-04-01

    This study illustrates differences in the cartilage degeneration in osteoarthritic knees in patients with more frequent hyperflexion activities of daily living compared with Western patients. Proximal tibial articular cartilage wear and cruciate ligament condition were assessed in Saudi Arabian and North American patients with varus osteoarthritis undergoing total knee arthroplasty. In anterior cruciate ligament (ACL) intact knees, there were significant differences in wear location, with a clearly more anterior pattern in Saudi Arabian knees. Complete ACL deficiency occurred in 25% of North American knees but only 14% of Saudi Arabian knees. These ACL-deficient knees showed the most severe cartilage wear in both groups and posterior medial wear patterns. Biomechanical descriptions of knee flexion and axial rotation during kneeling or squatting are consistent with the more pronounced anteromedial and posterolateral cartilage wear patterns observed on the Saudi Arabian knees. These observations provide insight into altered knee mechanics in 2 culturally different populations with different demands on knee flexion.

  20. Jumper's Knee (Patellar Tendonitis)

    MedlinePlus

    ... regularly play sports that involve a lot of repetitive jumping — like track and field (particularly high-jumping), basketball, volleyball, gymnastics, running, and soccer — can put a lot of strain on their knees. Jumper's knee can seem like a minor injury that isn't really that serious. Because of ...

  1. Tuberculosis of the knee

    PubMed Central

    Lidder, Surjit; Lang, Kathryn; Haroon, Mallick; Shahidi, Mitra; El-Guindi, Magdi

    2009-01-01

    Extrapulmonary manifestations of tuberculosis are reported in less than one in five cases with the knee affected in 8% after the spine and hip. We report a case of isolated highly erosive tuberculosis of the knee presenting in a previously fit Vietnamese woman. The difficulties of diagnosis, modalities of chemotherapeutic management, and surgical treatment are discussed. PMID:21808686

  2. Partial knee replacement

    MedlinePlus

    ... American Academy of Orthopedic Surgeons (AAOS). Treatment of osteoarthritis of the knee: Evidence-based guideline 2nd edition (summary). Rosemont, IL. ... al. American Academy of Orthopaedic Surgeons. Treatment of osteoarthritis of the knee (nonarthroplasty). J Am Acad Orthop Surg . 2009;17: ...

  3. Pneumatic osteoarthritis knee brace.

    PubMed

    Stamenović, Dimitrije; Kojić, Milos; Stojanović, Boban; Hunter, David

    2009-04-01

    Knee osteoarthritis is a chronic disease that necessitates long term therapeutic intervention. Biomechanical studies have demonstrated an improvement in the external adduction moment with application of a valgus knee brace. Despite being both efficacious and safe, due to their rigid frame and bulkiness, current designs of knee braces create discomfort and difficulties to patients during prolonged periods of application. Here we propose a novel design of a light osteoarthritis knee brace, which is made of soft conforming materials. Our design relies on a pneumatic leverage system, which, when pressurized, reduces the excessive loads predominantly affecting the medial compartment of the knee and eventually reverses the malalignment. Using a finite-element analysis, we show that with a moderate level of applied pressure, this pneumatic brace can, in theory, counterbalance a greater fraction of external adduction moment than the currently existing braces.

  4. Detection of Floating Inputs in Logic Circuits

    NASA Technical Reports Server (NTRS)

    Cash, B.; Thornton, M. G.

    1984-01-01

    Simple modification of oscilloscope probe allows easy detection of floating inputs or tristate outputs in digital-IC's. Oscilloscope probe easily modified with 1/4 W resistor and switch for detecting floating inputs in CMOS logic circuits.

  5. Strength Tests on Hulls and Floats

    NASA Technical Reports Server (NTRS)

    Matthaes, K

    1942-01-01

    The present report deals with strength tests on hulls and floats intended in part for the collection of construction data for the design of these components and in part for the stress analysis of the finished hulls and floats.

  6. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  7. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 15 2011-07-01 2011-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  8. New Directions in Floating-Point Arithmetic

    NASA Astrophysics Data System (ADS)

    Beebe, Nelson H. F.

    2007-12-01

    This article briefly describes the history of floating-point arithmetic, the development and features of IEEE standards for such arithmetic, desirable features of new implementations of floating-point hardware, and discusses work-in-progress aimed at making decimal floating-point arithmetic widely available across many architectures, operating systems, and programming languages.

  9. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or beach any boat, barge, or other floating object...

  10. Have Floating Rates Been a Success?

    ERIC Educational Resources Information Center

    Higham, David

    1983-01-01

    Floating exchange rates have not lived up to all expectations, but neither have they performed as badly as some critics have suggested. Examined are the impact of floating rates on balance of payments adjustment, domestic economic policy, and inflation and the claim that floating rates have displayed excessive fluctuations. (Author/RM)

  11. Advanced concepts in knee arthrodesis

    PubMed Central

    Wood, Jennifer H; Conway, Janet D

    2015-01-01

    The aim is to describe advanced strategies that can be used to diagnose and treat complications after knee arthrodesis and to describe temporary knee arthrodesis to treat infected knee arthroplasty. Potential difficult complications include nonunited knee arthrodesis, limb length discrepancy after knee arthrodesis, and united but infected knee arthrodesis. If a nonunited knee arthrodesis shows evidence of implant loosening or failure, then bone grafting the nonunion site as well as exchange intramedullary nailing and/or supplemental plate fixation are recommended. If symptomatic limb length discrepancy cannot be satisfactorily treated with a shoe lift, then the patient should undergo tibial lengthening over nail with a monolateral fixator or exchange nailing with a femoral internal lengthening device. If a united knee arthrodesis is infected, the nail must be removed. Then the surgeon has the option of replacing it with a long, antibiotic cement-coated nail. The authors also describe temporary knee arthrodesis for infected knee arthroplasty in patients who have the potential to undergo insertion of a new implant. The procedure has two goals: eradication of infection and stabilization of the knee. A temporary knee fusion can be accomplished by inserting both an antibiotic cement-coated knee fusion nail and a static antibiotic cement-coated spacer. These advanced techniques can be helpful when treating difficult complications after knee arthrodesis and treating cases of infected knee arthroplasty. PMID:25793160

  12. Flinking: Neither Floating nor Sinking.

    ERIC Educational Resources Information Center

    Wilson, Roger B.

    1993-01-01

    Describes an activity that challenges students to make an object that, when released under water, does not float up or sink down. The main concept this activity investigates is the density of ordinary objects in comparison to the density of water. (PR)

  13. Floating Ring-Groove Lapper

    NASA Technical Reports Server (NTRS)

    Williams, Robert L., Sr.; Williams, Robert L., Jr.; Chase, Timothy L.

    1992-01-01

    Tool fits out-of-round seal groove and laps it to fine finish without binding. Includes floating lapping pieces riding freely in groove, and are curved to match nominal diameter of groove. One lapping piece tightened so it does not move relative to disk.

  14. Float It Down the River.

    ERIC Educational Resources Information Center

    Brendzel, Sharon; Orfan, Lucy; Schuhmacher, Robert

    2000-01-01

    Presents an activity that involves students in a hands-on, creative project in which they use higher order thinking skills while designing and studying the basics of floating devices. Focuses on inquiry, a number of scientific principles, and the relationship between mathematics and science. (ASK)

  15. Designing seaplane hulls and floats

    NASA Technical Reports Server (NTRS)

    Benoit,

    1926-01-01

    Experimental data, such as the results of tank tests of models, render it possible to predict, at least in principle, as to how a hull or float of a given shape will comport itself. We will see further along, however, how uncertain these methods are and how they leave room for empiricism, which will reign for a long time yet in seaplane research bureaus.

  16. Evolution of knee kinematics three months after total knee replacement.

    PubMed

    Alice, Bonnefoy-Mazure; Stéphane, Armand; Yoshisama, Sagawa Junior; Pierre, Hoffmeyer; Domizio, Suvà; Hermes, Miozzari; Katia, Turcot

    2015-02-01

    In patients with debilitating knee osteoarthritis, total knee replacement is the most common surgical procedure. Numerous studies have demonstrated that knee kinematics one year after total knee replacement are still altered compared to the healthy joint. However, little is known regarding impairments and functional limitations of patients several months after total knee replacement. The aim of this study was to describe the evolution of the knee gait kinematic in patients with knee osteoarthritis before and three months after a total knee replacement. Ninety patients who were to undergo total knee replacement were included in this study. Twenty-three subjects were recruited as the control group. Three-dimensional gait analysis was performed before and three months after surgery. The spatio-temporal parameters and three-dimensional knee kinematics for the operated limb were evaluated during a comfortable gait and compared between groups (the before and after surgery groups and the control group). Three months after surgery, patients always walk with a slower gait velocity and lower knee flexion-extension movements compared to the control group. However, a degree of progress was observed in term of the stride and step length, gait velocity and knee alignment in the coronal plane. Our results suggest that the disability is still significant for most patients three months after total knee replacement. A better understand of the impairments and functional limitations following surgery would help clinicians design rehabilitation programs. Moreover, patients should be informed that rehabilitation after total knee replacement is a long process.

  17. Knee Conditioning Program

    MedlinePlus

    ... muscles help your knee joint absorb shock. Flexibility: Stretching the muscles that you strengthen is important for restoring range of motion and preventing injury. Gently stretching after strengthening exercises can help reduce muscle soreness ...

  18. Anterior knee pain

    MedlinePlus

    ... places extra stress on the kneecap (such as running, jumping or twisting, skiing, or playing soccer). You ... noticeable with: Deep knee bends Going down stairs Running downhill Standing up after sitting for awhile

  19. Prosthetic Knee Systems

    MedlinePlus

    ... must give support when people stand, allow smooth motion when people walk, and permit movement when people ... of knees and their options for stability and motion control would work best for them. There are ...

  20. Knee microfracture surgery

    MedlinePlus

    ... WM, Griesser MJ, Parker RD. Patellofemoral pain. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic ... ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 105. Miller RH, Azar FM. Knee injuries. In: Canale ST, ...

  1. Runners knee (image)

    MedlinePlus

    ... forces on the knee, such as a misaligned patella. Chondromalacia is treated with rest or immobilization and nonsteroidal anti-inflammatory drugs for pain. Physical therapy, especially ... alignment of the patella that cannot be corrected with therapy.

  2. Dashboard (in the) Knee

    PubMed Central

    Qureshi, AA; Green, TP

    2015-01-01

    We present the case of a 19-year-old individual presenting to an orthopaedic outpatient clinic several months following a dashboard knee injury during a road traffic accident with intermittent mechanical symptoms. Despite unremarkable examination findings and normal magnetic resonance imaging, the patient was identified subsequently as having an intra-articular plastic foreign body consistent with a piece of dashboard on arthroscopic knee assessment, the retrieval of which resulted in a complete resolution of symptoms. PMID:25723676

  3. A CMOS floating point multiplier

    NASA Astrophysics Data System (ADS)

    Uya, M.; Kaneko, K.; Yasui, J.

    1984-10-01

    This paper describes a 32-bit CMOS floating point multiplier. The chip can perform 32-bit floating point multiplication (based on the proposed IEEE Standard format) and 24-bit fixed point multiplication (two's complement format) in less than 78.7 and 71.1 ns, respectively, and the typical power dissipation is 195 mW at 10 million operations per second. High-speed multiplication techniques - a modified Booth's allgorithm, a carry save adder scheme, a high-speed CMOS full adder, and a modified carry select adder - are used to achieve the above high performance. The chip is designed for compatibility with 16-bit microcomputer systems, and is fabricated in 2 micron n-well CMOS technology; it contains about 23000 transistors of 5.75 x 5.67 sq mm in size.

  4. Float zone experiments in space

    NASA Technical Reports Server (NTRS)

    Verhoeven, J. D.; Noack, M. A.; Gill, W. N.; Hau, C. C.

    1984-01-01

    The molten zone/freezing crystal interface system and all the mechanisms were examined. If Marangoni convection produces oscillatory flows in the float zone of semiconductor materials, such as silicon, then it is unlikely that superior quality crystals can be grown in space using this process. The major goals were: (1) to determine the conditions for the onset of Marangoni flows in molten tin, a model system for low Prandtl number molten semiconductor materials; (2) to determine whether the flows can be suppressed by a thin oxide layer; and (3) based on experimental and mathematical analysis, to predict whether oscillatory flows will occur in the float zone silicon geometry in space, and if so, could it be suppressed by thin oxide or nitride films. Techniques were developed to analyze molten tin surfaces in a UHV system in a disk float zone geometry to minimize buoyancy flows. The critical Marangoni number for onset of oscillatory flows was determined to be greater than 4300 on atomically clean molten tin surfaces.

  5. Float Zone Experiments in Space

    NASA Technical Reports Server (NTRS)

    Verhoeven, J. D.

    1985-01-01

    The objective of this work has been to evaluate whether or not Marangoni flow could be suppressed in molten metals by the presence of very thin oxide films. Experimental work has been carried out on molten Sn under UHV conditions. A disk floating zone arrangement was developed to allow in situ Auger examination of molten surfaces. An electron energy loss technique was developed which allows detection of continuous tin oxide films of 6 A or greater. Experiments were planned to detect the effects of oxide formation upon Marangoni flow by measuring: (1) temperature profiles, (2) solid liquid interface shapes, (3) macrosegregation, and (4) the onset of oscillatory Marangoni flow by detecting oscillating temperature variations. Work on (4) showed that oscillatory temperature variations of frequency or = 10 Hz were not present in the disk float zone geometry under conditions of Ma = 4300 with an oxide free molten surface. The disk float zone geometry was modeled with a finite element analysis and temperature and velocity profiles were determined.

  6. Endodontic Epidemiology

    PubMed Central

    Shahravan, Arash; Haghdoost, Ali Akbar

    2014-01-01

    Epidemiology is the study of disease distribution and factors determining or affecting it. Likewise, endodontic epidemiology can be defined as the science of studying the distribution pattern and determinants of pulp and periapical diseases; specially apical periodontitis. Although different study designs have been used in endodontics, researchers must pay more attention to study designs with higher level of evidence such as randomized clinical trials. PMID:24688577

  7. 14 CFR 29.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 29.753 Section 29.753... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.753 Main float design. (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure...

  8. 14 CFR 27.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 27.753 Section 27.753... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.753 Main float design. (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure...

  9. Floating Point Multiply-Add-Subtract Implementation

    DTIC Science & Technology

    2014-11-07

    implementation receives two floating point numbers Ain and Bin. The floating point number is separated into component parts for processing. For this purpose...in FIG. 2 the mantissa of Ain is identified as Aman, and the mantissa of Bin is identified as Bman. The exponent of Ain is identified as Aexp, and...unit implementation 10 receives Ain and Bin in a floating point format that can be broken up into signs, mantissas, and exponents. These numbers

  10. Tank Tests of Twin Seaplane Floats

    NASA Technical Reports Server (NTRS)

    Herrman, H; Kempf, G; Kloess, H

    1928-01-01

    The following report contains the most essential data for the hydrodynamic portion of the twin-float problem. The following points were successfully investigated: 1) difference between stationary and nonstationary flow; 2) effect of the shape of the step; 3) effect of distance between floats; 4) effect of nose-heavy and tail-heavy moments; 5) effect of the shape of floats; 6) maneuverability.

  11. Acoustic Float for Marine Mammal Monitoring

    DTIC Science & Technology

    2009-09-30

    a matured technology, and is manufactured mainly by two companies, Webb Research (APEX) and Martec (PROVOR). Our original acoustic float, the...adding another microprocessor inside the float as originally planned, we have reprogrammed the APEX float processor board itself (apf9) by changing... echolocation clicks. The analysis revealed that by using ICI information, the ERMA detector was able to reduce the number of false positive detections to less

  12. The impact on seaplane floats during landing

    NASA Technical Reports Server (NTRS)

    Von Karman, TH

    1929-01-01

    In order to make a stress analysis of seaplane floats, and especially of the members connecting the floats with the fuselage, it is of great importance to determine the maximum pressure acting on the floats during landing. Here, the author gives a formula for maximum pressures during landing that permits one to apply experimental results to different bodies and different velocities. The author notes that the formula checks very well with experimental results.

  13. Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability.

    PubMed

    Gustafson, Jonathan A; Gorman, Shannon; Fitzgerald, G Kelley; Farrokhi, Shawn

    2016-01-01

    Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (p<0.01) and greater knee flexion excursions (p<0.01) compared to their knee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted.

  14. Runner's knee injuries.

    PubMed

    Lutter, L D

    1984-01-01

    In our series of running injuries 40% of all injuries have been related to the knee area. Over 20 million people in the United States run on a regular basis. Figures from large running sources show that 60% to 70% of individuals running regularly are injured severely enough to temporarily stop running. The figures are significant, not in the seriousness of the knee injury, but in the fact that seeking treatment for their knee problems. Orthopaedic surgeons, because of their ability to evaluate the entire lower extremity, become the central component for treatment of this large group of injured runners. As has been noted, the underlying biomechanical abnormality must be sought and dealt with or the symptoms return. By identification of the injured structure(s) integrated with biomechanical understanding, treatment can be developed on a rational basis, dealing with acute problems and prevention of future ones.

  15. Modeling International Space Station (ISS) Floating Potentials

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.; Gardner, Barbara

    2002-01-01

    The floating potential of the International Space Station (ISS) as a function of the electron current collection of its high voltage solar array panels is derived analytically. Based on Floating Potential Probe (FPP) measurements of the ISS potential and ambient plasma characteristics, it is shown that the ISS floating potential is a strong function of the electron temperature of the surrounding plasma. While the ISS floating potential has so far not attained the pre-flight predicted highly negative values, it is shown that for future mission builds, ISS must continue to provide two-fault tolerant arc-hazard protection for astronauts on EVA.

  16. Modeling International Space Station (ISS) Floating Potentials

    NASA Astrophysics Data System (ADS)

    Ferguson, Dale C.; Gardner, Barbara

    2002-05-01

    The floating potential of the International Space Station (ISS) as a function of the electron current collection of its high voltage solar array panels is derived analytically. Based on Floating Potential Probe (FPP) measurements of the ISS potential and ambient plasma characteristics, it is shown that the ISS floating potential is a strong function of the electron temperature of the surrounding plasma. While the ISS floating potential has so far not attained the pre-flight predicted highly negative values, it is shown that for future mission builds, ISS must continue to provide two-fault tolerant arc-hazard protection for astronauts on EVA.

  17. Cementless total knee arthroplasty

    PubMed Central

    Risitano, Salvatore; Sabatini, Luigi; Giachino, Matteo; Agati, Gabriele; Massè, Alessandro

    2016-01-01

    Interest for uncemented total knee arthroplasty (TKA) has greatly increased in recent years. This technique, less used than cemented knee replacement in the last decades, sees a revival thanks an advance in prosthetic design, instrumentation and operative technique. The related literature in some cases shows conflicting data on survival and on the revision’s rate, but in most cases a success rate comparable to cemented TKA is reported. The optimal fixation in TKA is a subject of debate with the majority of surgeons favouring cemented fixation. PMID:27162779

  18. Environmental epidemiology

    SciTech Connect

    Kopfler, F.C.; Craun, G.F.

    1986-01-01

    This volume is a compendium of peer-reviewed papers presented at the Symposium on Exposure Measurement and Evaluation Methods for Epidemiology, cosponsored in 1985 by the Health Effects Research Laboratory, USEPA, and the Division of Environmental Chemistry of the American Chemical Society. The book is divided into four sections: Use of Biological Monitoring to Assess Exposure, Epidemiologic Considerations for Assessing Exposure, Health and Exposure Data Bases, and Assessment of Exposure to Environmental Contaminants for Epidemiologic Studies. Both background papers and detailed reports of human studies are presented. The Biological Monitoring section contains reports of efforts to quantify adducts in blood and urine samples. In the section on Epidemiologic Considerations the feasibility of conducting epidemiologic studies of persons residing near hazardous waste sites and those exposed to arsenic in drinking water is described. The review of Data Bases includes government and industry water quality monitoring systems, the FDA Market Basket Study, major EPA air monitoring data, the National Database on Body Burden of Toxic chemicals, and the National Human Adipose Tissue Survey. Methods of assessing current exposure and estimating past exposure are detailed in the final section. Exposure to trichloroethylene in shower water, the relationship between water quality and cardiovascular disease, the contribution of environmental lead exposures to pediatric blood lead levels, and data from the TEAM study in which researchers compare indoor, outdoor, and breath analysis of air pollutant exposures are also discussed.

  19. Polygenic Epidemiology

    PubMed Central

    2016-01-01

    ABSTRACT Much of the genetic basis of complex traits is present on current genotyping products, but the individual variants that affect the traits have largely not been identified. Several traditional problems in genetic epidemiology have recently been addressed by assuming a polygenic basis for disease and treating it as a single entity. Here I briefly review some of these applications, which collectively may be termed polygenic epidemiology. Methodologies in this area include polygenic scoring, linear mixed models, and linkage disequilibrium scoring. They have been used to establish a polygenic effect, estimate genetic correlation between traits, estimate how many variants affect a trait, stratify cases into subphenotypes, predict individual disease risks, and infer causal effects using Mendelian randomization. Polygenic epidemiology will continue to yield useful applications even while much of the specific variation underlying complex traits remains undiscovered. PMID:27061411

  20. BLOCK-FLOATING-POINT REALIZATION OF DIGITAL FILTERS

    DTIC Science & Technology

    A realization for digital filters using block- floating - point arithmetic is proposed. A statistical model for roundoff noise is presented and used to compare block- floating - point with fixed-point and floating - point realizations.

  1. 14 CFR 27.753 - Main float design.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential that might be developed at the maximum altitude for which certification with that float is...

  2. 14 CFR 27.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential that might be developed at the maximum altitude for which certification with that float is...

  3. 14 CFR 29.753 - Main float design.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential that might be developed at the maximum altitude for which certification with that float is...

  4. 14 CFR 29.753 - Main float design.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential that might be developed at the maximum altitude for which certification with that float is...

  5. 14 CFR 27.753 - Main float design.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential that might be developed at the maximum altitude for which certification with that float is...

  6. 14 CFR 29.753 - Main float design.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential that might be developed at the maximum altitude for which certification with that float is...

  7. 14 CFR 29.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential that might be developed at the maximum altitude for which certification with that float is...

  8. 14 CFR 27.753 - Main float design.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential that might be developed at the maximum altitude for which certification with that float is...

  9. Self-stabilizing floating tower

    SciTech Connect

    Mougin, G.L.

    1980-12-30

    An offshore floating tower comprises two coaxial cylindrical enclosures interconnected by continuous radial bulkheads forming in the upper portion a ring of damping chambers and in the lower portion a ring of buoyancy tanksaround a bell-shaped chamber which is partially filled with air to produce pneumatic damping of vertical movement of the tower. The upper portion of the tower is separated from the lower portion by a horizontal slab. The upper portion of the internal enclosure is perforated in the vicinity of the horizontal slab.

  10. Reading Knee-Deep

    ERIC Educational Resources Information Center

    Jewett, Pamela

    2007-01-01

    Freire told his audience at a seminar at the University of Massachusetts, "You need to read knee-deep in texts, for deeper than surface meanings, and you need to know the words to be able to do it" (quoted in Cleary, 2003). In a children's literature class, fifteen teachers and I traveled along a path that moved us toward reading…

  11. Hypermobility and Knee Injuries.

    ERIC Educational Resources Information Center

    Steiner, Mark E.

    1987-01-01

    A review of research on the effect of hypermobility on knee injury indicates that greater than normal joint flexibility may be necessary for some athletic endeavors and that it may be possible to change one's underlying flexibility through training. However, for most athletes, inherited flexibility probably plays only a small role, if any, in…

  12. The effect of sustained static kneeling on kinetic and kinematic knee joint gait parameters.

    PubMed

    Kajaks, Tara; Costigan, Patrick

    2015-01-01

    Despite epidemiological evidence for kneeling as an occupational risk factor for knee osteoarthritis, biomechanical evidence is lacking. Gait knee joint mechanics, a common measure used to study knee osteoarthritis initiation, were used in the present study to investigate the effect of sustained static kneeling on the knee. Ten healthy male subjects (24.1 years ± 3.5) performed ten baseline walking trials, followed by a 30-min kneeling protocol and a second set of walking trials. Knee joint moments and angles were calculated during the stance phase. Within-subject root mean squared differences were compared within and between the pre- and post-kneeling gait trials. Differences were observed between the pre-kneeling and post-kneeling walking trails for flexion and adduction knee moments (0.12 Nm/kg ± 0.03, 0.07 Nm/kg ± 0.02) and angles (3.18° ± 1.22 and 1.64° ± 1.15), indicating that sustained static deep-knee flexion kneeling does acutely alter knee joint gait parameters.

  13. Custom Knee Device for Knee Contractures After Internal Femoral Lengthening.

    PubMed

    Bhave, Anil; Shabtai, Lior; Ong, Peck-Hoon; Standard, Shawn C; Paley, Dror; Herzenberg, John E

    2015-07-01

    The development of knee flexion contractures is among the most common problems and complications associated with lengthening the femur with an internal device or external fixator. Conservative treatment strategies include physical therapy, serial casting, and low-load prolonged stretching with commercially available splinting systems. The authors developed an individually molded, low-cost custom knee device with polyester synthetic conformable casting material to treat knee flexion contractures. The goal of this study was to evaluate the results of treatment with a custom knee device and specialized physical therapy in patients who had knee flexion contracture during femoral lengthening with an intramedullary lengthening femoral nail. This retrospective study included 23 patients (27 limbs) who underwent femoral lengthening with an internal device for the treatment of limb length discrepancy. All patients had a knee flexion contracture raging from 10° to 90° during the lengthening process and were treated with a custom knee device and specialized physical therapy. The average flexion contracture before treatment was 36°. The mean amount of lengthening was 5.4 cm. After an average of 3.8 weeks of use of the custom knee device, only 2 of 27 limbs (7.5%) had not achieved complete resolution of the flexion contracture. The average final extension was 1.4°. Only 7 of 27 limbs (26%) required additional soft tissue release. The custom knee device is an inexpensive and effective method for treating knee flexion contracture after lengthening with an internal device.

  14. Towards sensible floating-point arithmetic

    SciTech Connect

    Cody, W.J.

    1980-01-01

    Efforts to promote the development of high-quality transportable numerical software show that few, if any, of the floating-point arithmetic systems in existing computers are completely satisfactory for serious numerical computation. Examination of the defects in these systems leads to specifications for a sensible floating-point system from a numerical analyst's viewpoint. 1 table.

  15. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  16. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  17. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  18. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  19. Future float zone development in industry

    NASA Technical Reports Server (NTRS)

    Sandfort, R. M.

    1980-01-01

    The present industrial requirements for float zone silicon are summarized. Developments desired by the industry in the future are reported. The five most significant problems faced today by the float zone crystal growth method in industry are discussed. They are economic, large diameter, resistivity uniformity, control of carbon, and swirl defects.

  20. Vertical pump with free floating check valve

    DOEpatents

    Lindsay, Malcolm

    1980-01-01

    A vertical pump with a bottom discharge having a free floating check valve isposed in the outlet plenum thereof. The free floating check valve comprises a spherical member with a hemispherical cage-like member attached thereto which is capable of allowing forward or reverse flow under appropriate conditions while preventing reverse flow under inappropriate conditions.

  1. Whatever Floats Your Boat: A Design Challenge

    ERIC Educational Resources Information Center

    Kornoelje, Joanne; Roman, Harry T.

    2012-01-01

    This article presents a simple design challenge, based on the PBS program "Design Squad's" "Watercraft" activity that will prove engaging to most technology and engineering students. In this floating boat challenge, students are to build a boat that can float and support 25 pennies for at least 10 seconds--without leaking, sinking, or tipping…

  2. Epidemiological causality.

    PubMed

    Morabia, Alfredo

    2005-01-01

    Epidemiological methods, which combine population thinking and group comparisons, can primarily identify causes of disease in populations. There is therefore a tension between our intuitive notion of a cause, which we want to be deterministic and invariant at the individual level, and the epidemiological notion of causes, which are invariant only at the population level. Epidemiologists have given heretofore a pragmatic solution to this tension. Causal inference in epidemiology consists in checking the logical coherence of a causality statement and determining whether what has been found grossly contradicts what we think we already know: how strong is the association? Is there a dose-response relationship? Does the cause precede the effect? Is the effect biologically plausible? Etc. This approach to causal inference can be traced back to the English philosophers David Hume and John Stuart Mill. On the other hand, the mode of establishing causality, devised by Jakob Henle and Robert Koch, which has been fruitful in bacteriology, requires that in every instance the effect invariably follows the cause (e.g., inoculation of Koch bacillus and tuberculosis). This is incompatible with epidemiological causality which has to deal with probabilistic effects (e.g., smoking and lung cancer), and is therefore invariant only for the population.

  3. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  4. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  5. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  6. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  7. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  8. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  9. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  10. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  11. Knee Power Is an Important Parameter in Understanding Medial Knee Joint Load in Knee Osteoarthritis

    PubMed Central

    Calder, Kristina M; Acker, Stacey M; Arora, Neha; Beattie, Karen A; Callaghan, Jack P; Adachi, Jonathan D; Maly, Monica R

    2014-01-01

    Objective To determine the extent to which knee extensor strength and power explain variance in knee adduction moment (KAM) peak and impulse in clinical knee osteoarthritis (OA). Methods Fifty-three adults (mean ± SD age 61.6 ± 6.3 years, 11 men) with clinical knee OA participated. The KAM waveform was calculated from motion and force data and ensemble averaged from 5 walking trials. The KAM peak was normalized to body mass (Nm/kg). The mean KAM impulse reflected the mean total medial knee load during stride (Nm × seconds). For strength, the maximum knee extensor moment attained from maximal voluntary isometric contractions (MVIC) was normalized to body mass (Nm/kg). For power, the maximum knee extensor power during isotonic contractions, with the resistance set at 25% of MVIC, was normalized to body mass (W/kg). Covariates included age, sex, knee pain on the Knee Injury and Osteoarthritis Outcome Score, gait speed, and body mass index (BMI). Relationships of the KAM peak and impulse with strength and power were examined using sequential stepwise forward linear regressions. Results Covariates did not explain variance in the KAM peak. While extensor strength did not, peak knee extensor power explained 8% of the variance in the KAM peak (P = 0.02). Sex and BMI explained 24% of the variance in the KAM impulse (P < 0.05). Sex, BMI, and knee extensor power explained 31% of the variance in the KAM impulse (P = 0.02), with power contributing 7% (P < 0.05). Conclusion Knee extensor power was more important than isometric knee strength in understanding medial knee loads during gait. PMID:24920175

  12. Early clinical outcomes of floating platform mobile-bearing TKA: longitudinal comparison with fixed-bearing TKA.

    PubMed

    Kim, Tae Kyun; Chang, Chong Bum; Kang, Yeon Gwi; Chung, Byung June; Cho, Hyung Joon; Seong, Sang Cheol

    2010-07-01

    This study was conducted to longitudinally compare a new floating platform mobile-bearing (MB) prosthesis with an established fixed-bearing (FB) system with respect to early clinical outcomes in patients with bilateral TKAs using the MB prosthesis in one knee and the FB prosthesis in the other. Clinical outcomes (ROM, AKS and WOMAC scores, and side preference), evaluated at 6, 12 and 24 months postoperatively, were compared between knees fitted with the MB prosthesis (e.motion-FP) or the FB prosthesis (Genesis II) in 66 patients who underwent bilateral TKA. In addition, the same comparisons between the knees fitted with the MB prosthesis and the knees with the FB prosthesis were made separately in the subgroup of 33 patients implanted with a cruciate retaining FB (FB-CR) prosthesis and the other subgroup of 33 patients with a posteriorly stabilized FB (FB-PS) prosthesis in a knee. The floating platform MB prosthesis achieved comparable clinical outcomes to the FB prosthesis. No significant differences were found between the FB- and MB-implanted sides at any time with respect to the outcome scales, and temporal patterns were similar. However, comparisons of FB-CR and FB-PS patient groups revealed different temporal patterns. In the FB-CR group, most outcome scales were improved at 6 months, peaked at 12 months and then remained at this level at 24 months. In contrast, outcomes in the FB-PS group improved much faster to almost peak at 6 months, and then remained at this level. In the FB-CR group, more patients preferred the knee with fitted with a MB prosthesis at 6 months. In contrast, in the FB-PS group, no side preference for the MB prosthesis was observed, and more patients preferred knees implanted with the FB prosthesis at 12 and 24 months. This study demonstrates that this new mobile-bearing prosthesis, designed as a floating platform, provides satisfactory clinical performances that are comparable to those achieved using the established fixed

  13. Management of the Swollen Knee

    PubMed Central

    Stanish, William D.; Rice, William; Ratson, Gary; Loebenberg, Mark; Langley, Linda

    1988-01-01

    The primary-care physician plays a critical role in the diagnosis, initial treatment, and subsequent rehabilitation of many orthopedic conditions. The knee is the most frequently injured joint in sport medicine. The family physician must therefore be familiar with the etiology, cause, and natural history of problems related to the knee joint. The swollen knee is one of the most common ailments the family physician is asked to assess in his or her busy day-to-day practice of medicine. He or she must therefore remain abreast of the dynamic field of diagnostic procedures, treatments, and rehabilitative measures relating to many knee injuries. This paper deals with the more common causes of the acutely swollen knee, paying particular attention to the infected knee and the acute hemarthrosis. It should provide answers to most questions about diagnosis, initial treatment, and subsequent management of this problem. PMID:21264033

  14. Digital Epidemiology

    PubMed Central

    Salathé, Marcel; Bengtsson, Linus; Bodnar, Todd J.; Brewer, Devon D.; Brownstein, John S.; Buckee, Caroline; Campbell, Ellsworth M.; Cattuto, Ciro; Khandelwal, Shashank; Mabry, Patricia L.; Vespignani, Alessandro

    2012-01-01

    Mobile, social, real-time: the ongoing revolution in the way people communicate has given rise to a new kind of epidemiology. Digital data sources, when harnessed appropriately, can provide local and timely information about disease and health dynamics in populations around the world. The rapid, unprecedented increase in the availability of relevant data from various digital sources creates considerable technical and computational challenges. PMID:22844241

  15. Selectively lockable knee brace

    NASA Technical Reports Server (NTRS)

    Myers, Neill (Inventor); Shadoan, Mike (Inventor); Forbes, John (Inventor); Baker, Kevin (Inventor)

    1994-01-01

    A knee brace for aiding in rehabilitation of damaged leg muscles includes upper and lower housings, normally pivotable, one relative to the other about the knee joint axis of a patient. The upper housing is attachable to the thigh of the patient above the knee joint, while the lower housing is secured to a stirrup which extends downwardly along the patient's leg and is attached to the patient's shoe. An actuation rod is carried within the lower housing and is coupled to a cable. The upper and lower housings carry cooperative clutch/brake elements which normally are disengaged to permit relative movement between the upper and lower housings. When the cable is extended, the clutch/brake elements engage and lock the housings together. A heel strike mechanism fastened to the stirrup and the heel of the shoe is connected to the cable to selectively extend the cable and lock the brace in substantially any position when the patient places weight on the heel.

  16. Selectively Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    Myers, W. Neill (Inventor); Shadoan, Michael D. (Inventor); Forbes, John C. (Inventor); Baker, Kevin J. (Inventor); Rice, Darron C. (Inventor)

    1996-01-01

    A knee brace for aiding in rehabilitation of damaged leg muscles includes upper and lower housings normally pivotable one relative to the other about the knee joint axis of a patient. The upper housing is attachable to the thigh of the patient above the knee joint while the lower housing is secured to a stirrup which extends downwardly along the patient's leg and is attached to the patient's shoe. An actuation rod is carried within the lower housing and is coupled to a cable. The upper and lower housings carry cooperative clutch/brake elements which normally are disengaged to permit relative movement between the upper and lower housings. When the cable is extended the clutch/brake elements engage and lock the housings together. A heel strike mechanism fastened to the stirrup and the heel of the shoe is connected to the cable to selectively extend the cable and lock the brace in substantially any position when the patient places weight on the heel.

  17. Knee stabilization in patients with medial compartment knee osteoarthritis

    PubMed Central

    Lewek, Michael D.; Ramsey, Dan K.; Snyder-Mackler, Lynn; Rudolph, Katherine S.

    2005-01-01

    OBJECTIVE Individuals with medial knee osteoarthritis (MKOA) experience knee laxity and instability. Muscle stabilization strategies may influence the long term integrity of the joint. In this study we determined how individuals with medial knee OA respond to a rapid valgus knee movement to investigate the relationship between muscle stabilization strategies and knee instability. METHODS Twenty one subjects with MKOA and genu varum, and 19 control subjects were tested. Subjects stood with the test limb on a moveable platform that translated laterally to rapidly stress the knee’s medial periarticular structures and create a potentially destabilizing feeling at the knee joint. Knee motion and muscle responses were recorded. Subjects rated their knee instability with a self-report questionnaire about knee instability during daily activities. RESULTS Prior to plate movement the OA subjects demonstrated more medial muscle co-contraction (p=0.014). Following plate movement the OA subjects shifted less weight off the test limb (p = 0.013) and had more medial co-contraction (p=0.037). Those without instability had higher VMMH co-contraction than those who reported more instability (p=0.038). Knee stability correlated positively with VMMH co-contraction prior to plate movement (r = 0.459; p = 0.042). CONCLUSION This study demonstrates that individuals with MKOA attempt to stabilize the knee with greater medial muscle co-contraction in response to laxity that appears on only the medial side of the joint. This strategy presumably contributes to higher joint compression and could exacerbate joint destruction and needs to be altered to slow or stop the progression of the OA disease process. PMID:16142714

  18. Floating point arithmetic in future supercomputers

    NASA Technical Reports Server (NTRS)

    Bailey, David H.; Barton, John T.; Simon, Horst D.; Fouts, Martin J.

    1989-01-01

    Considerations in the floating-point design of a supercomputer are discussed. Particular attention is given to word size, hardware support for extended precision, format, and accuracy characteristics. These issues are discussed from the perspective of the Numerical Aerodynamic Simulation Systems Division at NASA Ames. The features believed to be most important for a future supercomputer floating-point design include: (1) a 64-bit IEEE floating-point format with 11 exponent bits, 52 mantissa bits, and one sign bit and (2) hardware support for reasonably fast double-precision arithmetic.

  19. New CFOA-based floating immittance emulators

    NASA Astrophysics Data System (ADS)

    Taher Abuelma'atti, Muhammad; Dhar, Sagar Kumar

    2016-12-01

    This paper presents four new topologies for emulating floating immittance functions. Each circuit uses two or three current-feedback operational-amplifiers (CFOAs) and three passive elements. The proposed topologies can emulate positive/negative lossless and lossy floating inductances, and positive/negative capacitance, resistance and inductance multipliers in addition to floating frequency-dependent positive and negative resistances. The functionality of the proposed circuits is verified using the Advanced Design System software and the AD844 CFOA. The simulation results are in excellent agreement with the theoretical calculations.

  20. Used float shoe recovered and tested

    SciTech Connect

    Colvard, R.L.

    1986-02-01

    A cement float valve has been recovered after it was circulated through and cemented downhole. It was retrieved by coring as part of an investigation into a cementing failure. The float equipment was then analyzed for downhole performance. This is believed to be the first instance of intact recovery of full-scale cementing hardware after it has been cemented in place. In this instance, the valve performed as designed. Flash set proved to be the probable cause of job failure. This article documents the job and includes photographs of the used float shoe and its components.

  1. Development of a knee joint motion simulator to evaluate deep knee flexion of artificial knee joints.

    PubMed

    Takano, Y; Ueno, M; Kiguchi, K; Ito, J; Mawatari, M; Hotokebuchi, T

    2008-01-01

    A purpose of this study is to examine the effect that quadriceps femoris force gives to rotation angle and joint reaction force of total knee prosthesis during deep knee flexion such as a unique sitting style called 'seiza' in Japanese. For the evaluation, we developed the knee motion simulator which could bend to 180 degrees continually simulating the passive flexion performed by clinicians. A total knee prosthesis, which is a specially-devised posterior stabilized type and capable of flexion up to 180 degrees, was inserted into bone model. And this prosthesis pulled by three kinds of quadriceps femoris forces to perform parameter study. The results obtained in this study were showed the same tendency with those in the past cadaveric experiment. It is suggested that the rotation angle and joint reaction force of total knee prosthesis are affected by shape of prosthesis, a vector of quadriceps femoris force, and bony aliments during deep knee flexion.

  2. Program Converts VAX Floating-Point Data To UNIX

    NASA Technical Reports Server (NTRS)

    Alves, Marcos; Chapman, Bruce; Chu, Eugene

    1996-01-01

    VAX Floating Point to Host Floating Point Conversion (VAXFC) software converts non-ASCII files to unformatted floating-point representation of UNIX machine. This is done by reading bytes bit by bit, converting them to floating-point numbers, then writing results to another file. Useful when data files created by VAX computer must be used on other machines. Written in C language.

  3. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  4. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  5. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  6. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  7. 14 CFR 23.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 23.753 Section 23.753... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Floats and Hulls § 23.753 Main float design. Each seaplane main float must meet the requirements of § 23.521....

  8. 14 CFR 27.751 - Main float buoyancy.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float buoyancy. 27.751 Section 27.751... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight of the rotorcraft in...

  9. 14 CFR 27.751 - Main float buoyancy.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Main float buoyancy. 27.751 Section 27.751... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight of the rotorcraft in...

  10. 14 CFR 27.751 - Main float buoyancy.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Main float buoyancy. 27.751 Section 27.751... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight of the rotorcraft in...

  11. 14 CFR 27.751 - Main float buoyancy.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Main float buoyancy. 27.751 Section 27.751... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight of the rotorcraft in...

  12. 14 CFR 27.751 - Main float buoyancy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float buoyancy. 27.751 Section 27.751... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.751 Main float buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight of the rotorcraft in...

  13. 14 CFR 23.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float design. 23.753 Section 23.753... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Floats and Hulls § 23.753 Main float design. Each seaplane main float must meet the requirements of § 23.521....

  14. Floating-gated memory based on carbon nanotube field-effect transistors with Si floating dots

    NASA Astrophysics Data System (ADS)

    Seike, Kohei; Fujii, Yusuke; Ohno, Yasuhide; Maehashi, Kenzo; Inoue, Koichi; Matsumoto, Kazuhiko

    2014-01-01

    We have fabricated a carbon nanotube field-effect transistor (CNTFET)-based nonvolatile memory device with Si floating dots. The electrical characteristics of this memory device were compared with those of devices with a HfO2 charge storage layer or Au floating dots. For a sweep width of 6 V, the memory window of the devices with the Si floating dots increased twofold as compared with that of the devices with the HfO2 layer. Moreover, the retention characteristics revealed that, for the device with the Au floating dots, the off-state had almost the same current as the on-state at the 400th s. However, the devices with the Si floating dots had longer-retention characteristics. The results indicate that CNTFET-based devices with Si floating dots are promising candidates for low-power consumption nonvolatile memory devices.

  15. Tests find hammering, fluid cutting, erosion cause float shoe failures

    SciTech Connect

    Stringfellow, B.

    1985-01-21

    The results of a systematic test program to evaluate float equipment performance are presented. The testing has destroyed, over an eightmonth period, 160 float valves, float shoes and float collars. A new float valve design with greater resistance to failure has been developed as a result of the testing. New float collars and float shoes are expected to provide the operator with a failure rate of less than 1 1/2% when used within design limits and under normal cementing conditions. Further testing objectives include: extension of operating temperature limits to include deep well and geothermal conditions, and evaluation of the effects of more abrasive mud and cement systems.

  16. Medial pivot knee in primary total knee arthroplasty.

    PubMed

    Atzori, Francesco; Salama, Wael; Sabatini, Luigi; Mousa, Shazly; Khalefa, Abdelrahman

    2016-01-01

    Total knee arthroplasty (TKA) with a medial pivot design was developed in order to mimic normal knee kinematics; the highly congruent medial compartment implant should improve clinical results and decrease contact stresses. Clinical and radiographic mid-term outcomes are satisfactory, but we need other studies to evaluate long-term results and indications for unusual cases.

  17. English Premiership Academy knee injuries: lessons from a 5 year study.

    PubMed

    Moore, Oliver; Cloke, David J; Avery, Peter J; Beasley, Ian; Deehan, David J

    2011-11-01

    This study addresses the epidemiology of knee injuries in adolescent males. Data were collected prospectively from 41 Premiership soccer academies over a 5 year period from July 2000 to June 2005. A total of 12,306 player seasons were registered in the U9 to the U16 age categories with a total of 1750 recordable injuries specific to the knee joint. There was a mean incidence of 0.71 (95% confidence interval ± 0.05) knee injuries per player per year, and a median of 17 (inter-quartile range 9-38) training days and 2 (inter-quartile range 1-4) matches missed per knee injury. Knee injuries were found to be most common in the 14-16 year age group. Six hundred and nine (35% of total) injuries were classed as severe resulting in more than 28 days' absence. Injuries were more likely to be sustained in a competitive or match-play environment (862 or 52%) than in training (796 or 48%), and a non-contact mechanism was implicated in 823 (55%) of recorded cases. Peaks in injury numbers were seen in early season and subsequent to the winter break. Sprain was the most common diagnosis recorded, with the medial collateral ligament affected in 23% of all knee injuries. Knee injuries are common in elite youth footballers. In this uninsured age group, it could be argued that earlier medical intervention may reduce long-term damage to the immature skeleton.

  18. Verification of floating-point software

    NASA Technical Reports Server (NTRS)

    Hoover, Doug N.

    1990-01-01

    Floating point computation presents a number of problems for formal verification. Should one treat the actual details of floating point operations, or accept them as imprecisely defined, or should one ignore round-off error altogether and behave as if floating point operations are perfectly accurate. There is the further problem that a numerical algorithm usually only approximately computes some mathematical function, and we often do not know just how good the approximation is, even in the absence of round-off error. ORA has developed a theory of asymptotic correctness which allows one to verify floating point software with a minimum entanglement in these problems. This theory and its implementation in the Ariel C verification system are described. The theory is illustrated using a simple program which finds a zero of a given function by bisection. This paper is presented in viewgraph form.

  19. Exploring Floating Concrete and Beam Design.

    ERIC Educational Resources Information Center

    Snell, Billie G.; Snell, Luke M.

    2002-01-01

    Presents two construction activities that address both state and federal science standards and encourage students to consider career options in mathematics and science. Includes floating concrete and paper bridge activities. (YDS)

  20. Floating patterns of metered dose inhalers.

    PubMed

    Wolf, B L; Cochran, K R

    1997-01-01

    As long as metered dose inhalers have existed, patients have sought a reliable method to determine if a given canister was still potent. Concerning beta agonists, the answer to this question may be lifesaving. Issues of compliance have made dating canisters or counting doses impractical. Likewise, previous claims of floating characteristics are unreliable. In tap water, we float-tested 13 commonly used inhalers three times each, observing variations as they were incrementally actuated, emptying their contents. One essential pattern was observed. Almost all prescription-size canisters sink when full; all float by the time one-third of their contents is gone. Orientation of prescription-size canisters changes in a distinct pattern especially near 90% depletion. Sample-size canisters showed some variance. Results suggest that the pharmaceutical industry should include individual floating characteristics as part of the package insert as they provide a reproducible means of gauging contents.

  1. Thumb polydactyly with a floating ulnar thumb.

    PubMed

    Hasegawa, Kenjiro; Namba, Yuzaburo; Kimata, Yoshihiro

    2013-01-01

    Thumb polydactyly is reported to be the most common congenital anomaly of the hand in Japan. The floating type is not particularly rare, accounting for 0.9 to 15% of all cases of thumb polydactyly. However, to the best of our knowledge, there has been only one case of thumb polydactyly with a floating ulnar thumb, reported by Onizuka. Herein, we report a case very similar to that reported by Onizuka. In our case, the vessels feeding the floating ulnar thumb branched from the superficial palmar arterial arch, and X-rays revealed triphalangism. In surgery, we not only reconstructed the morphology of the thumb, but also tried to preserve the sensation in the reconstructed thumb by transposing the digital nerve of the floating ulnar thumb to the radial thumb. In addition to thumb polydactyly, our case also showed hypoplasia of the thenar muscles.

  2. Preview of Mars Curiosity Parade Float

    NASA Video Gallery

    Jim Green, Director of the Science Mission Directorate Planetary Systems Division at NASA Headquarters, describes the replica of the Mars Curiosity Rover on the second NASA float in Monday's inaugu...

  3. Genetic Algorithms, Floating Point Numbers and Applications

    NASA Astrophysics Data System (ADS)

    Hardy, Yorick; Steeb, Willi-Hans; Stoop, Ruedi

    The core in most genetic algorithms is the bitwise manipulations of bit strings. We show that one can directly manipulate the bits in floating point numbers. This means the main bitwise operations in genetic algorithm mutations and crossings are directly done inside the floating point number. Thus the interval under consideration does not need to be known in advance. For applications, we consider the roots of polynomials and finding solutions of linear equations.

  4. Archimedes' floating bodies on a spherical Earth

    NASA Astrophysics Data System (ADS)

    Rorres, Chris

    2016-01-01

    Archimedes was the first to systematically find the centers of gravity of various solid bodies and to apply this concept in determining stable configurations of floating bodies. In this paper, we discuss an error in a proof developed by Archimedes that involves determining whether a uniform, spherical cap will float stably with its base horizontal in a liquid on a spherical Earth. We present a simpler, corrected proof and discuss aspects of his proof regarding a spherical cap that is not uniform.

  5. Multiple valued floating potentials of Langmuir probes

    NASA Technical Reports Server (NTRS)

    Nam, Cheol-Hee; Hershkowitz, N.; Cho, M. H.; Intrator, T.; Diebold, D.

    1988-01-01

    It is shown that Langmuir probes can have three different floating potentials in plasmas produced by a hot filament discharge in a multi-dipole device when the primary and secondary electron currents are comparable. The measured floating potential depends on the probe's initial condition - the most negative and the least negative potentials are found to be stable and the in-between value is found to be unstable. Results are compared to a simple theoretical model.

  6. New Generation Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A knee brace that uses Space Shuttle propulsion technology has moved a step closer to being available to help knee injury and stroke patients and may possibly benefit patients with birth defects, spinal cord injuries, and post-polio conditions. After years of hard work, inventors at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, have turned over the final design and prototype to industry partners at Horton's Orthotic Lab in Little Rock, Arkansas for further clinical testing. The device, called the Selectively Lockable Knee Brace, may mean faster, less painful rehabilitation for patients by allowing the knee to move when weight is not on the heel. Devices currently on the market lock the knee in a rigid, straight-leg position, or allow continuous free motion. Pictured here is a knee brace prototype being tested and fitted at Horton's Orthotic Lab. The knee brace is just one example of how space technology is being used to improve the lives of people on Earth. NASA's MSFC inventors Michael Shadoan and Neill Myers are space propulsion engineers who use the same mechanisms and materials to build systems for rockets that they used to design and develop the knee brace.

  7. Automatic locking orthotic knee device

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (Inventor)

    1993-01-01

    An articulated tang in clevis joint for incorporation in newly manufactured conventional strap-on orthotic knee devices or for replacing such joints in conventional strap-on orthotic knee devices is discussed. The instant tang in clevis joint allows the user the freedom to extend and bend the knee normally when no load (weight) is applied to the knee and to automatically lock the knee when the user transfers weight to the knee, thus preventing a damaged knee from bending uncontrollably when weight is applied to the knee. The tang in clevis joint of the present invention includes first and second clevis plates, a tang assembly and a spacer plate secured between the clevis plates. Each clevis plate includes a bevelled serrated upper section. A bevelled shoe is secured to the tank in close proximity to the bevelled serrated upper section of the clevis plates. A coiled spring mounted within an oblong bore of the tang normally urges the shoes secured to the tang out of engagement with the serrated upper section of each clevic plate to allow rotation of the tang relative to the clevis plate. When weight is applied to the joint, the load compresses the coiled spring, the serrations on each clevis plate dig into the bevelled shoes secured to the tang to prevent relative movement between the tang and clevis plates. A shoulder is provided on the tang and the spacer plate to prevent overextension of the joint.

  8. Exercise and the Knee Joint.

    ERIC Educational Resources Information Center

    Clarke, H. Harrison, Ed.

    1976-01-01

    This report by the President's Council on Physical Fitness and Sports examines the effects of various forms of physical exercise on the knee joint which, because of its vulnerability, is especially subject to injury. Discussion centers around the physical characteristics of the joint, commonly used measurements for determining knee stability,…

  9. Floating assembly of diatom Coscinodiscus sp. microshells.

    PubMed

    Wang, Yu; Pan, Junfeng; Cai, Jun; Zhang, Deyuan

    2012-03-30

    Diatoms have silica frustules with transparent and delicate micro/nano scale structures, two dimensional pore arrays, and large surface areas. Although, the diatom cells of Coscinodiscus sp. live underwater, we found that their valves can float on water and assemble together. Experiments show that the convex shape and the 40 nm sieve pores of the valves allow them to float on water, and that the buoyancy and the micro-range attractive forces cause the valves to assemble together at the highest point of water. As measured by AFM calibrated glass needles fixed in manipulator, the buoyancy force on a single floating valve may reach up to 10 μN in water. Turning the valves over, enlarging the sieve pores, reducing the surface tension of water, or vacuum pumping may cause the floating valves to sink. After the water has evaporated, the floating valves remained in their assembled state and formed a monolayer film. The bonded diatom monolayer may be valuable in studies on diatom based optical devices, biosensors, solar cells, and batteries, to better use the optical and adsorption properties of frustules. The floating assembly phenomenon can also be used as a self-assembly method for fabricating monolayer of circular plates.

  10. [Arthroscopic treatment for osteoarthritic knee].

    PubMed

    Bloom, Shlomo; Lebel, David; Cohen, Eugen; Atar, Dan; Rath, Ehud

    2008-04-01

    Osteoarthritis (OA) is the leading cause of knee morbidity. Age and overweight are the main risk factors for development of knee OA. The majority of patients respond to conservative treatment. For those who don't, surgical treatment is the only alternative. Arthroscopic surgery for the osteoarthritic knee is a well known procedure. Recently, numerous publications addressed the advantages of arthroscopic treatment for this indication. Some of the publications concluded that arthroscopic treatment for knee OA equals placebo. Others found temporary relief of symptoms. Among special subgroup of patients, in which acute pain exacerbation, mechanical block or early OA, utilizing arthroscopic techniques revealed satisfactory results. In this review, we discuss the indications and contraindications for arthroscopic treatment of the osteoarthritic knee according to the latest literature.

  11. Anterior knee pain.

    PubMed

    LLopis, Eva; Padrón, Mario

    2007-04-01

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries.

  12. [Pathogenesis of knee osteoarthrist].

    PubMed

    Bennemann, M; Hönle, W; Simank, H G; Schuh, A

    2007-06-21

    More than 20% of the population of over 60-year olds suffers from degenerative joint diseases of the lower extremities. The cause of primary osteoarthritis of the knee is still unknown. A multifactorial genesis is presumed that includes genetic, nutritional, hormonal and age-related factors. On the other hand, secondary osteoarthritis is a sequela of predisposing factors. The most frequent are axial deformities, pre-existing conditions or injuries. Pre-osteoarthritis appears as dysplasias and dystopias (abnormal presentation) of the patella and axial misalignments, incongruities and joint damage after fractures. The result is the mechanical destruction of the cartilage that, in turn, initiates a vicious circle of further cartilage loss.

  13. Prosthetic knee design by simulation

    SciTech Connect

    Hollerbach, K; Hollister, A

    1999-07-30

    Although 150,000 total knee replacement surgeries are performed annually in North America, current designs of knee prostheses have mechanical problems that include a limited range of motion, abnormal gait patterns, patellofemoral joint dysfunction, implant loosening or subsidence, and excessive wear. These problems fall into three categories: failure to reproduce normal joint kinematics, which results in altered limb function; bone-implant interface failure; and material failure. Modern computer technology can be used to design, prototype, and test new total knee implants. The design team uses the full range of CAD-CAM to design and produce implant prototypes for mechanical and clinical testing. Closer approximation of natural knee kinematics and kinetics is essential for improved patient function and diminished implant loads. Current knee replacement designs are based on 19th Century theories that the knee moves about a variable axis of rotation. Recent research has shown, however, that knee motion occurs about two fixed, offset axes of rotation. These aces are not perpendicular to the long axes of the bones or to each other, and the axes do not intersect. Bearing surfaces of mechanisms that move about axes of rotation are surfaces of revolution of those axes which advanced CAD technology can produce. Solids with surfaces of revolution for the two axes of rotation for the knee have been made using an HP9000 workstation and Structural Ideas Master Series CAD software at ArthroMotion. The implant's CAD model should closely replicate movements of the normal knee. The knee model will have a range of flexion-extension (FE) from -5 to 120 degrees. Movements include varus, valgus, internal and external rotation, as well as flexion and extension. The patellofemoral joint is aligned perpendicular to the FE axis and replicates the natural joint more closely than those of existing prostheses. The bearing surfaces will be more congruent than current designs and should

  14. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure. 572.166... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N)....

  15. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Knees and knee impact test procedure. 572.166... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N)....

  16. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  17. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  18. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  19. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  20. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.166... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N)....

  1. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.166... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N)....

  2. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  3. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.166... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N)....

  4. Exercise for knee osteoarthritis.

    PubMed

    Baker, K; McAlindon, T

    2000-09-01

    Adverse outcomes in knee osteoarthritis include pain, loss of function, and disability. These outcomes can have devastating effects on the quality of life of those suffering from the disease. Treatments have generally targeted pain, assuming that disability would improve as a direct result of improvements in pain. However, there is evidence to suggest that determinants of pain and disability differ. In general, treatments have been more successful at decreasing pain rather than disability. Many of the factors that lead to disability can be improved with exercise. Exercise, both aerobic and strength training, have been examined as treatments for knee osteoarthritis, with considerable variability in the results. The variability between studies may be due to differences in study design, exercise protocols, and participants in the studies. Although there is variability among studies, it is notable that a majority of the studies had a positive effect on pain and or disability. The mechanism of exercise remains unclear and merits future studies to better define a concise, clear exercise protocol that may have the potential for a public health intervention.

  5. Injury tolerance and moment response of the knee joint to combined valgus bending and shear loading.

    PubMed

    Bose, Dipan; Bhalla, Kavi S; Untaroiu, Costin D; Ivarsson, B Johan; Crandall, Jeff R; Hurwitz, Shepard

    2008-06-01

    Valgus bending and shearing of the knee have been identified as primary mechanisms of injuries in a lateral loading environment applicable to pedestrian-car collisions. Previous studies have reported on the structural response of the knee joint to pure valgus bending and lateral shearing, as well as the estimated injury thresholds for the knee bending angle and shear displacement based on experimental tests. However, epidemiological studies indicate that most knee injuries are due to the combined effects of bending and shear loading. Therefore, characterization of knee stiffness for combined loading and the associated injury tolerances is necessary for developing vehicle countermeasures to mitigate pedestrian injuries. Isolated knee joint specimens (n=40) from postmortem human subjects were tested in valgus bending at a loading rate representative of a pedestrian-car impact. The effect of lateral shear force combined with the bending moment on the stiffness response and the injury tolerances of the knee was concurrently evaluated. In addition to the knee moment-angle response, the bending angle and shear displacement corresponding to the first instance of primary ligament failure were determined in each test. The failure displacements were subsequently used to estimate an injury threshold function based on a simplified analytical model of the knee. The validity of the determined injury threshold function was subsequently verified using a finite element model. Post-test necropsy of the knees indicated medial collateral ligament injury consistent with the clinical injuries observed in pedestrian victims. The moment-angle response in valgus bending was determined at quasistatic and dynamic loading rates and compared to previously published test data. The peak bending moment values scaled to an average adult male showed no significant change with variation in the superimposed shear load. An injury threshold function for the knee in terms of bending angle and shear

  6. New Generation Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A knee brace that uses Space Shuttle propulsion technology has moved a step closer to being available to help knee injury and stroke patients and may possibly benefit patients with birth defects, spinal cord injuries, and post-polio conditions. After years of hard work, inventors at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, have turned over the final design and prototype to industry partners at Horton's Orthotic Lab in Little Rock, Arkansas for further clinical testing. The device, called the Selectively Lockable Knee Brace, may mean faster, less painful rehabilitation for patients by allowing the knee to move when weight is not on the heel. Devices currently on the market lock the knee in a rigid, straight-leg position, or allow continuous free motion. The knee brace is just one example of how space technology is being used to improve the lives of people on Earth. NASA's MSFC inventors Michael Shadoan and Neill Myers are space propulsion engineers who use the same mechanisms and materials to build systems for rockets that they used to design and develop the knee brace.

  7. Physiotherapy management of knee osteoarthritis.

    PubMed

    Page, Carolyn J; Hinman, Rana S; Bennell, Kim L

    2011-05-01

    Knee osteoarthritis (OA) is a prevalent chronic joint disease causing pain and disability. Physiotherapy, which encompasses a number of modalities, is a non-invasive treatment option in the management of OA. This review summarizes the evidence for commonly used physiotherapy interventions. There is strong evidence to show short-term beneficial effects of exercise on pain and function, although the type of exercise does not seem to influence treatment outcome. Delivery modes, including individual, group or home exercise are all effective, although therapist contact may improve benefits. Attention to improving adherence to exercise is needed to maximize outcomes in the longer-term. Knee taping applied with the aim of realigning the patella and unloading soft tissues can reduce pain. There is also evidence to support the use of knee braces in people with knee OA. Biomechanical studies show that lateral wedge shoe insoles reduce knee load but clinical trials do not support symptomatic benefits. Recent studies suggest individual shoe characteristics also affect knee load and there is current interest in the effect of modified shoe designs. Manual therapy, while not to be used as a stand-alone treatment, may be beneficial. In summary, although the research is not equivocal, there is sufficient evidence to indicate that physiotherapy interventions can reduce pain and improve function in those with knee OA.

  8. Airship-floated wind turbine

    SciTech Connect

    Watson, W. K.

    1985-01-01

    A wind turbine, by use of a tethered airship for support, may be designed for the economical recovery of power at heights of 2,000 feet or more above ground, at which height power density in the wind is typically three times the power density available to a conventionally supported wind turbine. Means can be added to such an airship-floated wind turbine which will permit its generators to be used to meet load demand even during periods of little or no wind. Described to this end is a wind turbine system which combines, among other novel features: a novel tether line system which provides access for men and materials to the supporting airship while in active service, a novel system for providing additional buoyant lift at the nose of the turbine-supporting airship to offset the vertical component of tension induced in the tether line by the downwind force exerted by the turbine blades, a novel bearing assembly at the nose of the supporting airship which permits the airship to rotate as a unit with the turbine it supports without causing a similar rotation of the tether line, a novel turbine airship structure which handles concentrated loads from the turbine efficiently and also permits the safe use of hydrogen for buoyancy, a novel ''space frame'' structure which supports the turbine blades and greatly reduces blade weight, a novel system for controlling turbine blade angle of incidence and for varying blade incidene in synchrony with blade angular position abut the turbine axis to provide greater control over airship movement, a novel system for locating propellor-driven generators out at the wind turbine perimeter and for using lightweight, high-RPM generators to produce electrical energy at a power line frequency, which greatly reduces the weight required to convert turbine blade torque into useful power, and a novel system for incorporating compressed air storage and combustion turbine components into the wind turbine's generator drive systems.

  9. Myofascial pain in patients waitlisted for total knee arthroplasty

    PubMed Central

    Henry, Richard; Cahill, Catherine M; Wood, Gavin; Hroch, Jennifer; Wilson, Rosemary; Cupido, Tracy; VanDenKerkhof, Elizabeth

    2012-01-01

    BACKGROUND: Knee pain is one of the major sources of pain and disability in developed countries, particularly in aging populations, and is the primary indication for total knee arthroplasty (TKA) in patients with osteoarthritis (OA). OBJECTIVES: To determine the presence of myofascial pain in OA patients waitlisted for TKA and to determine whether their knee pain may be alleviated by trigger point injections. METHODS: Following ethics approval, 25 participants were recruited from the wait list for elective unilateral primary TKA at the study centre. After providing informed consent, all participants were examined for the presence of active trigger points in the muscles surrounding the knee and received trigger point injections of bupivacaine. Assessments and trigger point injections were implemented on the first visit and at subsequent visits on weeks 1, 2, 4 and 8. Outcome measures included the Timed Up and Go test, Brief Pain Inventory, Centre for Epidemiologic Studies Depression Scale, State-Trait Anxiety Inventory and Short-Form McGill Pain Questionnaire. RESULTS: Myofascial trigger points were identified in all participants. Trigger point injections significantly reduced pain intensity and pain interference, and improved mobility. All participants had trigger points identified in medial muscles, most commonly in the head of the gastrocnemius muscle. An acute reduction in pain and improved functionality was observed immediately following intervention, and persisted over the eight-week course of the investigation. CONCLUSION: All patients had trigger points in the vastus and gastrocnemius muscles, and 92% of patients experienced significant pain relief with trigger point injections at the first visit, indicating that a significant proportion of the OA knee pain was myofascial in origin. Further investigation is warranted to determine the prevalence of myofascial pain and whether treatment delays or prevents TKA. PMID:23061082

  10. Floating seal system for rotary devices

    DOEpatents

    Banasiuk, Hubert A.

    1983-01-01

    This invention relates to a floating seal system for rotary devices to reduce gas leakage around the rotary device in a duct and across the face of the rotary device to an adjacent duct. The peripheral seal bodies are made of resilient material having a generally U-shaped cross section wherein one of the legs is secured to a support member and the other of the legs forms a contacting seal against the rotary device. The legs of the peripheral seal form an extended angle of intersection of about 10.degree. to about 30.degree. in the unloaded condition to provide even sealing forces around the periphery of the rotary device. The peripheral seal extends around the periphery of the support member except where intersected by radial seals which reduce gas leakage across the face of the rotary device and between adjacent duct portions. The radial seal assembly is fabricated from channel bars, the smaller channel bar being secured to the divider of the support member and a larger inverted rigid floating channel bar having its legs freely movable over the legs of the smaller channel bar forming therewith a tubular channel. A resilient flexible tube is positioned within the tubular channel for substantially its full length to reduce gas leakage across the tubular channel. A spacer extends beyond the face of the floating channel near each end of the floating channel a distance to provide desired clearance between the floating channel and the face of the rotary device.

  11. Battery charging in float vs. cycling environments

    SciTech Connect

    COREY,GARTH P.

    2000-04-20

    In lead-acid battery systems, cycling systems are often managed using float management strategies. There are many differences in battery management strategies for a float environment and battery management strategies for a cycling environment. To complicate matters further, in many cycling environments, such as off-grid domestic power systems, there is usually not an available charging source capable of efficiently equalizing a lead-acid battery let alone bring it to a full state of charge. Typically, rules for battery management which have worked quite well in a floating environment have been routinely applied to cycling batteries without full appreciation of what the cycling battery really needs to reach a full state of charge and to maintain a high state of health. For example, charge target voltages for batteries that are regularly deep cycled in off-grid power sources are the same as voltages applied to stand-by systems following a discharge event. In other charging operations equalization charge requirements are frequently ignored or incorrectly applied in cycled systems which frequently leads to premature capacity loss. The cause of this serious problem: the application of float battery management strategies to cycling battery systems. This paper describes the outcomes to be expected when managing cycling batteries with float strategies and discusses the techniques and benefits for the use of cycling battery management strategies.

  12. Floating seal system for rotary devices

    DOEpatents

    Banasiuk, H.A.

    1983-08-23

    This invention relates to a floating seal system for rotary devices to reduce gas leakage around the rotary device in a duct and across the face of the rotary device to an adjacent duct. The peripheral seal bodies are made of resilient material having a generally U-shaped cross section wherein one of the legs is secured to a support member and the other of the legs forms a contacting seal against the rotary device. The legs of the peripheral seal form an extended angle of intersection of about 10[degree] to about 30[degree] in the unloaded condition to provide even sealing forces around the periphery of the rotary device. The peripheral seal extends around the periphery of the support member except where intersected by radial seals which reduce gas leakage across the face of the rotary device and between adjacent duct portions. The radial seal assembly is fabricated from channel bars, the smaller channel bar being secured to the divider of the support member and a larger inverted rigid floating channel bar having its legs freely movable over the legs of the smaller channel bar forming therewith a tubular channel. A resilient flexible tube is positioned within the tubular channel for substantially its full length to reduce gas leakage across the tubular channel. A spacer extends beyond the face of the floating channel near each end of the floating channel a distance to provide desired clearance between the floating channel and the face of the rotary device. 5 figs.

  13. Floating mechanism of a small liquid marble

    PubMed Central

    Ooi, Chin Hong; Plackowski, Chris; Nguyen, Anh V.; Vadivelu, Raja K.; John, James A. St.; Dao, Dzung Viet; Nguyen, Nam-Trung

    2016-01-01

    Flotation of small solid objects and liquid droplets on water is critical to natural and industrial activities. This paper reports the floating mechanism of liquid marbles, or liquid droplets coated with hydrophobic microparticles. We used X-ray computed tomography (XCT) to acquire cross-sectional images of the floating liquid marble and interface between the different phases. We then analysed the shape of the liquid marble and the angles at the three-phase contact line (TPCL). We found that the small floating liquid marbles follow the mechanism governing the flotation of solid objects in terms of surface tension forces. However, the contact angles formed and deformation of the liquid marble resemble that of a sessile liquid droplet on a thin, elastic solid. For small liquid marbles, the contact angle varies with volume due to the deformability of the interface. PMID:26902930

  14. Floating zone melting of cadmium telluride

    NASA Technical Reports Server (NTRS)

    Chang, Wen-Ming; Regel, L. L.; Wilcox, W. R.

    1992-01-01

    To produce superior crystals of cadmium telluride, floating zone melting in space has been proposed. Techniques required for floating zone melting of cadmium telluride are being developed. We have successfully float-zoned cadmium telluride on earth using square rods. A resistance heater was constructed for forming the molten zone. Evaporation of the molten zone was controlled by adding excess cadmium to the growth ampoule combined with heating of the entire ampoule. An effective method to hold the feed rod was developed. Slow rotation of the growth ampoule was proven experimentally to be necessary to achieve a complete symmetric molten zone. Most of the resultant cylindrical rods were single crystals with twins. Still needed is a suitable automatic method to control the zone length. We tried a fiber optical technique to control the zone length, but experiments showed that application of this technique to automate zone length control is unlikely to be successful.

  15. Cephalometric floating norms for North American adults.

    PubMed

    Franchi, L; Baccetti, T; McNamara, J A

    1998-12-01

    Floating norms provide a method of analysis that uses the variability of the associations among suitable cephalometric measures, on the basis of a regression model combining both sagittal and vertical skeletal parameters. This study establishes floating norms for the description of the individual skeletal pattern in North American adults. The method is based on the correlations among the following craniofacial measurements: SNA, SNB, NL-NSL, ML-NSL, and NSBa. The results are given in a graphical box-like form. This easy, practical procedure allows for the identification of either individual harmonious craniofacial features or anomalous deviations from the individual norm. The use of cephalometric floating norms may be helpful for diagnosis and treatment planning in orthognathic surgery and dentofacial orthopedics.

  16. Anterior Knee Pain (Chondromalacia Patellae).

    ERIC Educational Resources Information Center

    Garrick, James G.

    1989-01-01

    This article presents a pragmatic approach to the definition, diagnosis, and management of anterior knee pain. Symptoms and treatment are described. Emphasis is on active involvement of the patient in the rehabilitation exercise program. (IAH)

  17. Arthroplasty of a Charcot knee

    PubMed Central

    Babazadeh, Sina; Stoney, James D.; Lim, Keith; Choong, Peter F.M.

    2010-01-01

    The Charcot knee - or neuropathic arthropathy - presents a considerable challenge to the orthopaedic surgeon. Caused by a combination of sensory, motor and autonomic neuropathy, it was originally described as an arthritic sequelae of neurosyphilis. In today's western orthopaedics it is more often caused by diabetes. A Charcot knee is often symptomatically painful and unstable. Traditional management has usually been conservative or arthrodesis, with limited success. Arthroplasty of a Charcot joint has commonly been avoided at all costs. However, in the right patient, using the right technique, arthroplasty can significantly improve the symptoms of a Charcot joint. This article explores the evidence surrounding the role of arthroplasty in the management of a Charcot knee. Arthroplasty is compared to other forms of treatment and specific patient demographics and surgical techniques are explored in an attempt to define the role of arthroplasty in the management of a Charcot knee. PMID:21808708

  18. Bowlegs and Knock-Knees

    MedlinePlus

    ... Infections Learning Disabilities Obesity Orthopedic Prevention Sexually Transmitted ... and Knock-Knees Page Content Article Body Toddlers’ legs often have a bowed appearance. In fact, many children have bowing of the ...

  19. Knee Brace Would Lock And Unlock Automatically

    NASA Technical Reports Server (NTRS)

    Myers, Neill; Forbes, John; Shadoan, Mike; Baker, Kevin

    1995-01-01

    Proposed knee brace designed to aid rehabilitation of person who suffered some muscle damage in leg. Not limited to locking in straight-leg position and, instead, locks at any bend angle. Does not prevent knee from bearing weight. Instead, knee brace allows knee to bear weight and locks only when foot and lower leg bear weight. Thus, brace prevents flexion that wearer desired to prevent but could not prevent because of weakened muscles. Knee bends freely to exercise knee-related muscles. Knee brace strapped at upper end to leg above knee, and anchored at lower end by stirrup under foot. Joint mechanism (identical mechanisms used in left and right assemblies) allows knee joint to flex freely except when weight applied to heel.

  20. [Congenital knee dislocation: case report].

    PubMed

    Arvinius, C; Luque, R; Díaz-Ceacero, C; Marco, F

    2016-01-01

    Congenital knee dislocation is an infrequent condition with unknown etiology. In some cases it occurs as an isolated condition, while in others it coexists with associated conditions or syndromes. The treatment of congenital knee dislocation is driven by the severity and flexibility of the deformity. The literature includes from serial casting or the Pavlik harness to quadriceps tendon plasty or femoral osteotomies. We report herein the case of a congenital dislocation treated with serial casting with a good outcome.

  1. Improvements in floating point addition/subtraction operations

    DOEpatents

    Farmwald, P.M.

    1984-02-24

    Apparatus is described for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  2. Hydrodynamic Tests of Models of Seaplane Floats

    NASA Technical Reports Server (NTRS)

    Eula, Antonio

    1935-01-01

    This report contains the results of tank tests carried out at free trim on seventeen hulls and floats of various types. The data as to the weight on water, trim, and relative resistance for each model are plotted nondimensionally and are referenced both to the total weight and to the weight on water. Despite the fact that the experiments were not made systematically, a study of the models and of the test data permits nevertheless some general deductions regarding the forms of floats and their resistance. One specific conclusion is that the best models have a maximum relative resistance not exceeding 20 percent of the total weight.

  3. Well casing float shoe or collar

    SciTech Connect

    Kaufman, H. J.

    1985-08-06

    A well casing float shoe which is adapted for a variety of well installations consists of a tubular metal shoe member filled with cementitious material having a longitudinal bore surrounding and securing in place a tubular metal sleeve. The metal sleeve is threaded at the top and bottom ends to receive a variety of sizes and types of check valves. A well casing float collar has the same construction, but the tubular shoe member is replaced with a tubular metal collar with threaded connections both above and below the cementitious filler material.

  4. Tibia valga morphology in osteoarthritic knees: importance of preoperative full limb radiographs in total knee arthroplasty.

    PubMed

    Alghamdi, Ahmed; Rahmé, Michel; Lavigne, Martin; Massé, Vincent; Vendittoli, Pascal-André

    2014-08-01

    Osteoarthritis of the knee is associated with deformities of the lower limb. Tibia valga is a contributing factor to lower limb alignment in valgus knees. We evaluated 97 valgus knees and 100 varus knees. Long-leg films were taken in weight bearing with both knees in full extension. For valgus knees, 52 knees (53%) had a tibia valga deformity. Average tibia valgus deformation was 5.0°. For varus knees, there was only 1 case of tibia valga (1%), with a deformation of 2.5°. The aim of this study was to assess the prevalence of primary tibia valga in valgus and varus knees and understand how it affects our approach to total knee arthroplasty (TKA). We recommend having full-leg length films when planning for TKA in valgus knees.

  5. Changes in knee kinematics following total knee arthroplasty.

    PubMed

    Akbari Shandiz, Mohsen; Boulos, Paul; Saevarsson, Stefan Karl; Yoo, Sam; Miller, Stephen; Anglin, Carolyn

    2016-04-01

    Total knee arthroplasty (TKA) changes the knee joint in both intentional and unintentional, known and unknown, ways. Patellofemoral and tibiofemoral kinematics play an important role in postoperative pain, function, satisfaction and revision, yet are largely unknown. Preoperative kinematics, postoperative kinematics or changes in kinematics may help identify causes of poor clinical outcome. Patellofemoral kinematics are challenging to record since the patella is obscured by the metal femoral component in X-ray and moves under the skin. The purpose of this study was to determine the kinematic degrees of freedom having significant changes and to evaluate the variability in individual changes to allow future study of patients with poor clinical outcomes. We prospectively studied the 6 degrees of freedom patellofemoral and tibiofemoral weightbearing kinematics, tibiofemoral contact points and helical axes of rotation of nine subjects before and at least 1 year after total knee arthroplasty using clinically available computed tomography and radiographic imaging systems. Normal kinematics for healthy individuals were identified from the literature. Significant differences existed between pre-TKA and post-TKA kinematics, with the post-TKA kinematics being closer to normal. While on average the pre-total knee arthroplasty knees in this group displayed no pivoting (only translation), individually only five knees displayed this behaviour (of these, two showed lateral pivoting, one showed medial pivoting and one showed central pivoting). There was considerable variability postoperatively as well (five central, two lateral and two medial pivoting). Both preop and postop, flexion behaviour was more hinge-like medially and more rolling laterally. Helical axes were more consistent postop for this group. An inclusive understanding of the pre-TKA and post-TKA kinematics and changes in kinematics due to total knee arthroplasty could improve implant design, patient diagnosis and

  6. MRI of knee ligament injury and reconstruction.

    PubMed

    Farshad-Amacker, Nadja A; Potter, Hollis G

    2013-10-01

    Knee ligament instability may lead to meniscal and chondral damage, resulting in early osteoarthritis. Due to its superior soft tissue contrast and avoidance of harmful ionizing radiation, MRI has become the most important imaging modality for early recognition of structural defects of the knee joint. This review aims to the understanding of MRI appearances of knee ligament structures associated with knee instability, and to review the common patterns of altered knee mechanics that lead to ligament failure. Normal anatomy of the knee ligaments, pathologic conditions, and postsurgical appearances of the anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament, and posterolateral corner are described.

  7. Medial unicondylar knee arthroplasty: technical pearls

    PubMed Central

    BONIFORTI, FILIPPO

    2015-01-01

    Unicondylar knee arthroplasty implantation is extremely demanding as the prosthesis needs to be integrated in the natural anatomy of the knee. It ensures the integrity of the natural knee kinematic. Some studies and registries data have shown lower success rate in comparison with total knee arthroplasty, and patient-related factors may have an impact on outcome. While, better results have been published by high volume centres. The indications for surgery should be reconsidered critically, even if medial osteoarthritis of the knee remains the most common. This article sets out the diagnostic, and surgical steps in order to fine tuning the unicompartmental replacement of the knee. PMID:26605256

  8. 40 CFR 65.44 - External floating roof (EFR).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false External floating roof (EFR). 65.44... (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Storage Vessels § 65.44 External floating roof (EFR). (a) EFR... emissions by using an external floating roof shall comply with the design requirements listed in...

  9. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  10. 33 CFR 144.01-10 - Equipment for life floats.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Equipment for life floats. 144.01... for life floats. (a) Each lifefloat shall be provided with a painter. This painter shall be a manila... 1/2 inch in diameter. (b) Each life float must have a water light of an approved automatic...

  11. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  12. 33 CFR 144.01-10 - Equipment for life floats.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Equipment for life floats. 144.01... for life floats. (a) Each lifefloat shall be provided with a painter. This painter shall be a manila... 1/2 inch in diameter. (b) Each life float must have a water light of an approved automatic...

  13. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  14. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  15. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Life floats and buoyant apparatus. 131.870 Section 131... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant...

  16. 33 CFR 144.01-10 - Equipment for life floats.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Equipment for life floats. 144.01... for life floats. (a) Each lifefloat shall be provided with a painter. This painter shall be a manila... 1/2 inch in diameter. (b) Each life float must have a water light of an approved automatic...

  17. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Life floats and buoyant apparatus. 131.870 Section 131... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant...

  18. 33 CFR 144.01-10 - Equipment for life floats.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Equipment for life floats. 144.01... for life floats. (a) Each lifefloat shall be provided with a painter. This painter shall be a manila... 1/2 inch in diameter. (b) Each life float must have a water light of an approved automatic...

  19. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Life floats and buoyant apparatus. 131.870 Section 131... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant...

  20. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant apparatus... 46 Shipping 4 2011-10-01 2011-10-01 false Life floats and buoyant apparatus. 131.870 Section...

  1. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant apparatus... 46 Shipping 4 2010-10-01 2010-10-01 false Life floats and buoyant apparatus. 131.870 Section...

  2. Improving the performance of floating solar pool covers

    SciTech Connect

    Cole, M.A.; Lowrey, P. . Dept. of Mechanical Engineering)

    1992-11-01

    Experimental and analytical analyses are presented for the evaluation of heat transfer through floating solar swimming pool covers. Two improved floating solar swimming pool cover designs are proposed and investigated in this paper. The results conclusively show that both new cover designs should have significantly better performance than conventional floating solar swimming pool covers.

  3. 14 CFR 25.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 25.753 Section 25.753 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Floats and Hulls § 25.753 Main float...

  4. 14 CFR 25.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float design. 25.753 Section 25.753 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Floats and Hulls § 25.753 Main float...

  5. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hull and auxiliary float strength. 29.757 Section 29.757 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  6. Variability in risk factors for knee injury in construction.

    PubMed

    Tak, Sangwoo; Paquet, Victor; Woskie, Susan; Buchholz, Bryan; Punnett, Laura

    2009-02-01

    This study investigated sources of variance in exposure to risk factors for knee pain in a variety of highway construction trades, operations, and tasks. Over 15,000 discrete observations of leg postures and weights handled were made on 120 construction workers in five construction trades, in nine operations over 79 days. The contributions of trade, operation, task, and worker to the variability in work time spent kneeling, squatting, and carrying loads were evaluated with multilevel random effects models. Construction operation and task explained about 20% to 30% of total variation in kneeling, squatting, and carrying loads. There was a large unexplained component of variance thought to represent day-to-day variability of exposure within task. Reliable assessments of knee exposures require multiple days to accommodate the high variability of exposures among operations and tasks and over time. These sources of variability should be carefully considered in efforts to estimate exposures to knee loading for epidemiologic or intervention studies. Homogenous exposure groups are not easily defined from the readily available organizational features of construction work.

  7. Subtropical Productivity from Profiling Floats and Gliders

    NASA Astrophysics Data System (ADS)

    Nicholson, D. P.; Johnson, K. S.; Karl, D. M.

    2015-12-01

    Since 2007 profiling floats equipped with dissolved oxygen and nitrate sensors have been released from the Hawaii Ocean Time-series (HOT) and Bermuda Atlantic Time-series Study (BATS) sites and can be calibrated using time-series observations. More recent deployments have also included bio-optical and pH sensors. Gliders with oxygen sensors and bio-optics have been intermittently deployed near HOT Station ALOHA since 2008 and at BATS since 2014. While gliders maintain a restricted survey region near the time-series stations, profiling floats drifted widely across the subtropical gyres. Multiple floats and gliders enables a cotemporaneous comparison of biogeochemical processes across gyres. These platforms enable observations on spatial scales from submesoscale to basin scale and on temporal scales from diel to interannual. Here, I focus on the spatiotemporal variability of nitrate and oxygen mass balances in the North Pacific and North Atlantic subtropical gyres using a data-assimilating and float-tracking 1D upper ocean model.

  8. Dealing with Human Death: The Floating Perspective.

    ERIC Educational Resources Information Center

    Kenyon, Gary M.

    1991-01-01

    Explores approach to dealing with human death. Describes floating perspective, based on insights from Choron and Jaspers, as suggesting it is possible to deal with human death by refraining from taking ultimate position on the problem. Position encourages openness to death. Examines role of anxiety and describes possible meaningful outcomes of…

  9. Intraoperative passive knee kinematics during total knee arthroplasty surgery.

    PubMed

    Young, Kathryn L; Dunbar, Michael J; Richardson, Glen; Astephen Wilson, Janie L

    2015-11-01

    Surgical navigation systems for total knee arthroplasty (TKA) surgery are capable of capturing passive three-dimensional (3D) angular joint movement patterns intraoperatively. Improved understanding of patient-specific knee kinematic changes between pre and post-implant states and their relationship with post-operative function may be important in optimizing TKA outcomes. However, a comprehensive characterization of the variability among patients has yet to be investigated. The objective of this study was to characterize the variability within frontal plane joint movement patterns intraoperatively during a passive knee flexion exercise. Three hundred and forty patients with severe knee osteoarthritis (OA) received a primary TKA using a navigation system. Passive kinematics were captured prior to (pre-implant), and after prosthesis insertion (post-implant). Principal component analysis (PCA) was used to capture characteristic patterns of knee angle kinematics among patients, to identify potential patient subgroups based on these patterns, and to examine the subgroup-specific changes in these patterns between pre- and post-implant states. The first four extracted patterns explained 99.9% of the diversity within the frontal plane angle patterns among the patients. Post-implant, the magnitude of the frontal plane angle shifted toward a neutral mechanical axis in all phenotypes, yet subtle pattern (shape of curvature) features of the pre-implant state persisted.

  10. Anterior knee pain after total knee arthroplasty: a narrative review.

    PubMed

    Petersen, Wolf; Rembitzki, Ingo Volker; Brüggemann, Gerd-Peter; Ellermann, Andree; Best, Raymond; Koppenburg, Andreas Gösele-; Liebau, Christian

    2014-02-01

    Anterior knee pain is one of the most common causes of persistent problems after implantation of a total knee replacement. It can occur in patients with or without patellar resurfacing. As a result of the surgical procedure itself many changes can occur which may affect the delicate interplay of the joint partners in the patello-femoral joint. Functional causes of anterior knee pain can be distinguished from mechanical causes. The functional causes concern disorders of inter- and intramuscular coordination, which can be attributed to preoperative osteoarthritis. Research about anterior knee pain has shown that not only the thigh muscles but also the hip and trunk stabilising muscles may be responsible for the development of a dynamic valgus malalignment. Dynamic valgus may be a causative factor for patellar maltracking. The mechanical causes of patello-femoral problems after knee replacement can be distinguished according to whether they increase instability in the joint, increase joint pressure or whether they affect the muscular lever arms. These causes include offset errors, oversizing, rotational errors of femoral or tibial component, instability, maltracking and chondrolysis, patella baja and aseptic loosening. In these cases, reoperation or revision is often necessary.

  11. The incidence of knee and anterior cruciate ligament injuries over one decade in the Belgian Soccer League.

    PubMed

    Quisquater, Laurent; Bollars, Peter; Vanlommel, Luc; Claes, Steven; Corten, Kristoff; Bellemans, Johan

    2013-10-01

    In an epidemiological study we assessed the evolution in the incidence and possible risk factors of knee injuries, especially anterior cruciate ligament (ACL) injuries, in Belgian soccer over one decade. Two soccer seasons (1999-2000 and 2009-2010) were compared and 56,364 injury reports registered by the KBVB-URBSFA were retrieved. Knee injuries totaled 9.971 cases, 5.495 in the first season (1999-2000) and 4.476 in the second (2009-2010): a significant decrease in incidence from 1.5 per 100 players in 2000 to 1.2 knee injuries in 2010. Six percent of all knee injuries were ACL injuries. The reported incidence of ACL tears slightly increased from 0.081 to 0.084 per 100 players. Female gender, competition and age over 18 years were prognosticators for ACL injuries. Enhanced prevention programs for ACL injuries, especially in those sports groups are warranted.

  12. Comparison of knee gait kinematics of workers exposed to knee straining posture to those of non-knee straining workers.

    PubMed

    Gaudreault, Nathaly; Hagemeister, Nicola; Poitras, Stéphane; de Guise, Jacques A

    2013-06-01

    Workers exposed to knee straining postures, such as kneeling and squatting, may present modifications in knee gait kinematics that can make them vulnerable to osteoarthritis. In this study, knee kinematics of workers exposed to occupational knee straining postures (KS workers) were compared to those of non-knee straining (non-KS) workers. Eighteen KS workers and 20 non-KS workers participated in the study. Three-dimensional gait kinematic data were recorded at the knee using an electromagnetic motion tracking system. The following parameters were extracted from flexion/extension, adduction/abduction and internal/external rotation angle data and used for group comparisons: knee angle at initial foot contact, peak angles, minimal angles and angle range during the entire gait cycle. Group comparisons were performed with Student t-tests. In the sagittal plane, KS workers had a greater knee flexion angle at initial foot contact, a lower peak knee flexion angle during the swing phase and a lower angle range than non-KS workers (p<0.05). In the frontal plane, all parameters indicated that KS workers had their knees more adducted than non-KS workers. External/internal rotation range was greater for KS workers. This study provides new knowledge on work related to KS postures and knee kinematics. The results support the concept that KS workers might exhibit knee kinematics that are different from those of non-KS workers.

  13. Knee Replacement: MedlinePlus Health Topic

    MedlinePlus

    ... Arthritis and Musculoskeletal and Skin Diseases) Also in Spanish Knee Replacement (Mayo Foundation for Medical Education and ... American Academy of Orthopaedic Surgeons) - PDF Also in Spanish Total Knee Replacement (Arthroplasty) (Beyond the Basics) (UpToDate) ...

  14. [What's new about total knee arthroplasty].

    PubMed

    Dao Trong, Mai Lang; Helmy, Näder

    2013-10-30

    Osteoarthritis of the knee is one of the most common problems in the orthopedic practice and its surgical technique is still challenging. This Mini-Review presents patient specific cutting blocks for the implantation of a total knee arthroplasty.

  15. Knee joint forces: prediction, measurement, and significance

    PubMed Central

    D’Lima, Darryl D.; Fregly, Benjamin J.; Patil, Shantanu; Steklov, Nikolai; Colwell, Clifford W.

    2011-01-01

    Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined. PMID:22468461

  16. Automatically Locking/Unlocking Orthotic Knee Joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1994-01-01

    Proposed orthotic knee joint locks and unlocks automatically, at any position within range of bend angles, without manual intervention by wearer. Includes tang and clevis, locks whenever wearer transfers weight to knee and unlocks when weight removed. Locking occurs at any angle between 45 degrees knee bend and full extension.

  17. Knee Replacement - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Knee Replacement (Arabic) العربية Bilingual PDF Health Information Translations Bosnian (Bosanski) Total Knee Replacement Potpuna zamjena koljena - Bosanski (Bosnian) Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) Total Knee Replacement 全膝关节置换 - 简体中文 ( ...

  18. Effect of exercise and gait retraining on knee adduction moment in people with knee osteoarthritis.

    PubMed

    Khalaj, Nafiseh; Abu Osman, Noor A; Mokhtar, Abdul H; Mehdikhani, Mahboobeh; Wan Abas, Wan A B

    2014-02-01

    The knee adduction moment represents the medial knee joint load, and greater value is associated with higher load. In people with knee osteoarthritis, it is important to apply proper treatment with the least side effects to reduce knee adduction moment and, consequently, reduce medial knee joint load. This reduction may slow the progression of knee osteoarthritis. The research team performed a literature search of electronic databases. The search keywords were as follows: knee osteoarthritis, knee adduction moment, exercise program, exercise therapy, gait retraining, gait modification and knee joint loading. In total, 12 studies were selected, according to the selection criteria. Findings from previous studies illustrated that exercise and gait retraining programs could alter knee adduction moment in people with knee osteoarthritis. These treatments are noninvasive and nonpharmacological which so far have no or few side effects, as well as being low cost. The results of this review revealed that gait retraining programs were helpful in reducing the knee adduction moment. In contrast, not all the exercise programs were beneficial in reducing knee adduction moment. Future studies are needed to indicate best clinical exercise and gait retraining programs, which are most effective in reducing knee adduction moment in people with knee osteoarthritis.

  19. Intraoperative passive kinematics of osteoarthritic knees before and after total knee arthroplasty.

    PubMed

    Siston, Robert A; Giori, Nicholas J; Goodman, Stuart B; Delp, Scott L

    2006-08-01

    Total knee arthroplasty is a successful procedure to treat pain and functional disability due to osteoarthritis. However, precisely how a total knee arthroplasty changes the kinematics of an osteoarthritic knee is unknown. We used a surgical navigation system to measure normal passive kinematics from 7 embalmed cadaver lower extremities and in vivo intraoperative passive kinematics on 17 patients undergoing primary total knee arthroplasty to address two questions: How do the kinematics of knees with advanced osteoarthritis differ from normal knees?; and, Does posterior substituting total knee arthroplasty restore kinematics towards normal? Osteoarthritic knees displayed a decreased screw-home motion and abnormal varus/valgus rotations between 10 degrees and 90 degrees of knee flexion when compared to normal knees. The anterior-posterior motion of the femur in osteoarthritic knees was not different than in normal knees. Following total knee arthroplasty, we found abnormal varus/valgus rotations in early flexion, a reduced screw-home motion when compared to the osteoarthritic knees, and an abnormal anterior translation of the femur during the first 60 degrees of flexion. Posterior substituting total knee arthroplasty does not appear to restore normal passive varus/valgus rotations or the screw motion and introduces an abnormal anterior translation of the femur during intraoperative evaluation.

  20. International Lymphoma Epidemiology Consortium

    Cancer.gov

    The InterLymph Consortium, or formally the International Consortium of Investigators Working on Non-Hodgkin's Lymphoma Epidemiologic Studies, is an open scientific forum for epidemiologic research in non-Hodgkin's lymphoma.

  1. Epidemiology of Alcoholism.

    ERIC Educational Resources Information Center

    Helzer, John E.

    1987-01-01

    Reviews the application of epidemiology to alcoholism. Discusses measurement and diagnostic issues and reviews studies of the prevalence of alcoholism, its risk factors, and the contributions of epidemiology to our knowledge of treatment and prevention. (Author/KS)

  2. Early osteoarthritis of the knee.

    PubMed

    Madry, Henning; Kon, Elizaveta; Condello, Vincenzo; Peretti, Giuseppe M; Steinwachs, Matthias; Seil, Romain; Berruto, Massimo; Engebretsen, Lars; Filardo, Giuseppe; Angele, Peter

    2016-06-01

    There is an increasing awareness on the importance in identifying early phases of the degenerative processes in knee osteoarthritis (OA), the crucial period of the disease when there might still be the possibility to initiate treatments preventing its progression. Early OA may show a diffuse and ill-defined involvement, but also originate in the cartilage surrounding a focal lesion, thus necessitating a separate assessment of these two entities. Early OA can be considered to include a maximal involvement of 50 % of the cartilage thickness based on the macroscopic ICRS classification, reflecting an OARSI grade 4. The purpose of this paper was to provide an updated review of the current status of the diagnosis and definition of early knee OA, including the clinical, radiographical, histological, MRI, and arthroscopic definitions and biomarkers. Based on current evidence, practical classification criteria are presented. As new insights and technologies become available, they will further evolve to better define and treat early knee OA.

  3. [Dermato-epidemiology].

    PubMed

    Apfelbacher, C J; Diepgen, T L; Weisshaar, E

    2011-11-01

    Dermato-epidemiology is an important scientific discipline which investigates skin diseases using epidemiological methods. Epidemiology is the science of the distribution and determinants of disease in specified populations. We describe fundamental terms of dermato-epidemiology (measures of disease occurrence, measures of risk), different study types (observational studies, interventional studies), the selection of statistical tests, bias and confounding as well as the principles of evidence-based dermatology, and give illustrative examples.

  4. Cancer Epidemiology Matters Blog

    Cancer.gov

    The Cancer Epidemiology Matters blog helps foster a dialogue between the National Cancer Institute's (NCI) Epidemiology and Genomics Research Program (EGRP), extramural researchers, and other individuals, such as clinicians, community partners, and advocates, who are interested in cancer epidemiology and genomics.

  5. [Rehabilitation after total knee arthroplasty of hip and knee].

    PubMed

    Jansen, E; Brienza, S; Gierasimowicz-Fontana, A; Matos, C; Reynders-Frederix-Dobre, C; HateM, S M

    2015-09-01

    Numbers of total hip and knee arthroplasties are increasing on a regular basis. Clinical pathways tend to shorten the duration of hospitalization in acute care after surgery. Therefore, the preoperative preparation of the patient and his abilities for postoperative rehabilitation should be carefully addressed. Before the surgical intervention, it is recommended that the patient receives an educational program and a physical preparation. After the surgical intervention, the patient can benefit from a home-based rehabilitation program supervised by a physiotherapist, if there were no preoperative reasons for prolonging the hospital stay and if the surgery took place without complications. Some patients may benefit from postsurgical rehabilitation in a specialized locomotor rehabilitation long-stay care unit. The indications for inpatient multidisciplinary rehabilitation are : two simultaneous arthroplasties, revision of a previous hip or knee arthroplasty, postsurgical complications, advanced age, comorbidities influencing the rehabilitation process, social difficulties, necessity for adaptation of the environment, insufficient or unadapted out-patient (para)medical care. The goals of the rehabilitation treatment depend on the patient's characteristics and environment, on the properties of the prosthesis and on the postsurgical complications. The functional prognosis of a total joint arthroplasty of the knee or hip is excellent, provided that there are no post-surgical complications and that the patient benefits from adequate rehabilitation therapy. The present paper describes the different phases of rehabilitation treatment and the general and specific complications of total hip and knee arthroplasties that may influence the rehabilitation outcome.

  6. Basic knee arthroscopy part 3: diagnostic arthroscopy.

    PubMed

    Ward, Benjamin D; Lubowitz, James H

    2013-11-01

    Knee arthroscopy is an important diagnostic and therapeutic tool in the management of disorders of the knee. In a series of 4 articles, the basics of knee arthroscopy are reviewed. In this article (part 3), step-by-step diagnostic arthroscopy is reviewed. Diagnostic arthroscopy is a crucial skill for diagnosing intra-articular disorders of the knee including meniscal, synovial, ligamentous, and articular cartilage pathology. Mastery of the basic diagnostic arthroscopy is a critical tool for orthopaedic surgeons treating disorders of the knee.

  7. Basic Knee Arthroscopy Part 1: Patient Positioning

    PubMed Central

    Ward, Benjamin D.; Lubowitz, James H.

    2013-01-01

    Knee arthroscopy is an important diagnostic and therapeutic tool in the management of disorders of the knee. In a series of 4 articles, the basics of knee arthroscopy are reviewed. In this article (part 1), patient positioning, tourniquet placement, and draping are reviewed. Meticulous attention to these details allows surgical access to the compartments of the knee. A circumferential leg holder or a lateral post allows the application of varus and valgus forces to open the medial and lateral compartments of the knee. PMID:24892015

  8. Floating behavior of hydrophobic glass spheres.

    PubMed

    Liu, Xinjie; Wang, Xiaolong; Liang, Yongmin; Zhou, Feng

    2009-08-15

    When a hydrophobic solid sphere is floating on water or salt solutions with different concentrations, it is at equilibrium under the impact of gravity, buoyancy force, and curvature force, the component of surface tension in the vertical direction. We have changed the diameters of the spheres and the concentrations of the two selected salts, NaCl and NaNO(3), to study the floating behaviors of these spheres and the contributions of surface tension and buoyancy force to their floatation. Generally speaking, the surface tension plays a more important role than the buoyancy force when the gravity is small, but the buoyancy force plays an identical or a more important role when the spheres are big enough. The wettability of the spheres significantly influences the height below the contact perimeter especially in salt solutions. The theoretical calculation meniscus slope angles at the sphere three-phase contact line are in agreement with experimental results.

  9. Capillary deposition of advected floating particles

    NASA Astrophysics Data System (ADS)

    Dressaire, Emilie; Debaisieux, Aymeric; Gregori, Federico

    2016-11-01

    The deposition and aggregation of particles flowing through a confined environment can dramatically hinder the transport of suspensions. Yet, the mechanisms responsible for the deposition of particles in shear flow are not fully understood. Here, we use an experimental model system in which floating particles are advected on the surface of a water channel and deposited on fixed obstacles through attractive capillary effects. By varying the flow rate of the liquid, the wetting properties and size of the particles and obstacles, we can tune the magnitude of the capillary and hydrodynamic forces that determine the probability of deposition and the equilibrium position on the substrate. We show that arrays of obstacles can be designed to efficiently capture the floating particles advected by the flow.

  10. Floating production systems planned for Italy, Nigeria

    SciTech Connect

    Not Available

    1985-05-01

    EMH has signed a contract to design, fabricate and install a permanent deepwater, gravity-based single-point mooring (SPM) system and floating oil storage facility in Societa Energio Montedison's (SEM) Vega field off Italy. The design of the system is described. The system is designed to accomodate production rates of 75,000 bpd. The oil will be loaded from the storage tanker into shuttle tankers which will take it to area refineries. The shuttle tankers can moor either in tandem or side-by-side for loading. Also described in this paper are three Nigerian offshore fields -- Akam, Adanga and Ebughu -- being developed by Ashland Oil. They will be brought onstream through the use of an integrated floating production, storage and offloading (FPSO) system. Production from all three fields will be piped to a central manifold platform to which a tanker will be permanently moored via a soft-yoke mooring system.

  11. Floating vs flying: A propulsion energy comparison

    NASA Technical Reports Server (NTRS)

    Marbury, F.

    1975-01-01

    Floating craft are compared to those that fly. Drag/weight for floaters is shown to be proportional to v squared/L, while for flyers it is independent of size and speed. The transportation market will therefore assign airships to lower speeds than airplanes, and will favor large airship sizes. Drag of an airship is shown to be only 11 percent of submarine drag at equal displacement and speed, raising the possibility that airships can compete with some types of ships.

  12. Ships as future floating farm systems?

    PubMed

    Moustafa, Khaled

    2016-09-29

    Environmental and agriculture challenges such as severe drought, desertification, sprawling cities and shrinking arable lands in large regions in the world compel us to think about alternative and sustainable farming systems. Ongoing projects to build floating cities in the sea suggest that building specific ships for farming purposes (as farming ships or farming boats) would also be attainable to introduce new farming surfaces and boost food production worldwide to cope with food insecurity issues.

  13. Floating gate transistors as biosensors (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Frisbie, C. Daniel

    2016-11-01

    Electrolyte gated transistors (EGTs) are a sub-class of thin film transistors that are extremely promising for biological sensing applications. These devices employ a solid electrolyte as the gate insulator; the very large capacitance of the electrolyte results in low voltage operation and high transconductance or gain. This talk will describe the fabrication of floating gate EGTs and their use as ricin sensors. The critical performance metrics for EGTs compared with other types of TFTs will also be reviewed.

  14. Knee extension torque variability after exercise in ACL reconstructed knees.

    PubMed

    Goetschius, John; Kuenze, Christopher M; Hart, Joseph M

    2015-08-01

    The purpose of this study was to compare knee extension torque variability in patients with ACL reconstructed knees before and after exercise. Thirty two patients with an ACL reconstructed knee (ACL-R group) and 32 healthy controls (control group) completed measures of maximal isometric knee extension torque (90° flexion) at baseline and following a 30-min exercise protocol (post-exercise). Exercise included 30-min of repeated cycles of inclined treadmill walking and hopping tasks. Dependent variables were the coefficient of variation (CV) and raw-change in CV (ΔCV): CV = (torque standard deviation/torque mean x 100), ΔCV = (post-exercise - baseline). There was a group-by-time interaction (p = 0.03) on CV. The ACL-R group demonstrated greater CV than the control group at baseline (ACL-R = 1.07 ± 0.55, control = 0.79 ± 0.42, p = 0.03) and post-exercise (ACL-R = 1.60 ± 0.91, control = 0.94 ± 0.41, p = 0.001). ΔCV was greater (p = 0.03) in the ACL-R group (0.52 ± 0.82) than control group (0.15 ± 0.46). CV significantly increased from baseline to post-exercise (p = 0.001) in the ACL-R group, while the control group did not (p = 0.06). The ACL-R group demonstrated greater knee extension torque variability than the control group. Exercise increased torque variability more in the ACL-R group than control group.

  15. Complex function of the knee joint: the current understanding of the knee.

    PubMed

    Hirschmann, Michael T; Müller, Werner

    2015-10-01

    Since the early years of orthopaedics, it is a well-known fact that anatomy follows function. During the evolution of mankind, the knee has been optimally adapted to the forces and loads acting at and through the knee joint. However, anatomy of the knee joint is variable and the only constant is its complex function. In contrast to the time of open surgery, nowadays the majority of reconstructive knee surgery is done arthroscopically. Keyhole surgery is less invasive, but on the backside, the knee surgeon lacks daily visualisation of the complex open anatomy. As open anatomical knowledge is less present in our daily practice, it is even more important to highlight this complex anatomy and function of the knee. It is the purpose of this review to perform a systematic review of knee anatomy, highlight the complex function of the knee joint and present an overview about recent and current knowledge about knee function. Level of evidence Systematic review, Level IV.

  16. Can generic knee joint models improve the measurement of osteoarthritic knee kinematics during squatting activity?

    PubMed

    Clément, Julien; Dumas, Raphaël; Hagemeister, Nicola; de Guise, Jaques A

    2017-01-01

    Knee joint kinematics derived from multi-body optimisation (MBO) still requires evaluation. The objective of this study was to corroborate model-derived kinematics of osteoarthritic knees obtained using four generic knee joint models used in musculoskeletal modelling - spherical, hinge, degree-of-freedom coupling curves and parallel mechanism - against reference knee kinematics measured by stereo-radiography. Root mean square errors ranged from 0.7° to 23.4° for knee rotations and from 0.6 to 9.0 mm for knee displacements. Model-derived knee kinematics computed from generic knee joint models was inaccurate. Future developments and experiments should improve the reliability of osteoarthritic knee models in MBO and musculoskeletal modelling.

  17. FPP [Floating Potential Probe] Results, Final Report

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.

    2007-01-01

    The Floating Potential Probe (FPP) operated on the International Space Station (ISS) from December 2000 to April 2001. During that time, it took many measurements of the ISS floating potential and the electron density and temperature. Those measurements were used as inputs to the Environments WorkBench (EWB) model of ISS potentials (originally developed by SAIC, but now sometimes called the Boeing model) that is used even today to predict charging levels for ISS. FPP is now completely defunct, having been removed and ejected from ISS. With the advent of the new Floating Potential Monitoring Unit (FPMU) on ISS, and the beginning of ISS operations with two large solar array panels instead of just one, a review of FPP measurements can offer comparisons with the new FPMU data and perhaps improve the accuracy of future ISS charging predictions. In particular, FPP measurements during times of low electron temperature and high electron density (the times of worst ISS charging) will be brought forward for comparison with the newly obtained FPMU data.

  18. Floating debris in the Mediterranean Sea.

    PubMed

    Suaria, Giuseppe; Aliani, Stefano

    2014-09-15

    Results from the first large-scale survey of floating natural (NMD) and anthropogenic (AMD) debris (>2 cm) in the central and western part of the Mediterranean Sea are reported. Floating debris was found throughout the entire study area with densities ranging from 0 to 194.6 items/km(2) and mean abundances of 24.9 AMD items/km(2) and 6.9 NMD items/km(2) across all surveyed locations. On the whole, 78% of all sighted objects were of anthropogenic origin, 95.6% of which were petrochemical derivatives (i.e. plastic and styrofoam). Maximum AMD densities (>52 items/km(2)) were found in the Adriatic Sea and in the Algerian basin, while the lowest densities (<6.3 items/km(2)) were observed in the Central Tyrrhenian and in the Sicilian Sea. All the other areas had mean densities ranging from 10.9 to 30.7 items/km(2). According to our calculations, more than 62 million macro-litter items are currently floating on the surface of the whole Mediterranean basin.

  19. Liquid encapsulated float zone process and apparatus

    NASA Technical Reports Server (NTRS)

    Naumann, Robert J. (Inventor); Frazier, Donald O. (Inventor); Lehoczky, Sandor L. (Inventor); Vlasse, Marcus (Inventor); Facemire, Barbara R. (Inventor)

    1988-01-01

    The process and apparatus for growing crystals using float zone techniques are described. A rod of crystalline materials is disposed in a cylindrical container, leaving a space between the rod and container walls. This space is filled with an encapsulant, selected to have a slightly lower melting point than the crystalline material. The rod is secured to a container end cap at one end and to a shaft at its other end. A piston slides over the rod and provides pressure to prevent loss of volatile components upon melting of the rod. Prior to melting the rod the container is first heated to melt the encapsulant, with any off-gas from this step being vented to a cavity behind the piston. The piston moves slightly forward owing to volume change upon melting of the encapsulant, and the vent passageway is closed. The container is then moved longitudinally through a heated zone to progressively melt sections of the rod as in conventional float zone processes. The float zone technique may be used in the microgravity environment of space.

  20. Borofloat and Starphire Float Glasses: A Comparison

    SciTech Connect

    Wereszczak, Andrew A.; Anderson Jr., Charles E.

    2014-10-28

    Borofloat® borosilicate float glass and Starphire® soda-lime silicate float glass are used in transparent protective systems. They are known to respond differently in some ballistic and triaxial loading conditions, and efforts are underway to understand the causes of those differences. Toward that, a suite of test and material characterizations were completed in the present study on both glasses so to identify what differences exist among them. Compositional, physical properties, elastic properties, flaw size distributions and concentrations, tensile/flexure strength, fracture toughness, spherical indentation and hardness, transmission electron microscopy, striae, high pressure responses via diamond anvil cell testing, laser shock differences, and internal porosity were examined. Differences between these two float glasses were identified for many of these properties and characteristics, and the role of three (striae, high pressures where permanent densification can initiate, and sub-micron-sized porosity) lack understanding and deserve further attention. Lastly, the contributing roles of any of those properties or characteristics to triaxial or ballistic loading responses are not definitive; however, they provide potential correlations that may lead to improved understanding and management of loading responses in glasses used in transparent protective systems.

  1. Borofloat and Starphire Float Glasses: A Comparison

    DOE PAGES

    Wereszczak, Andrew A.; Anderson Jr., Charles E.

    2014-10-28

    Borofloat® borosilicate float glass and Starphire® soda-lime silicate float glass are used in transparent protective systems. They are known to respond differently in some ballistic and triaxial loading conditions, and efforts are underway to understand the causes of those differences. Toward that, a suite of test and material characterizations were completed in the present study on both glasses so to identify what differences exist among them. Compositional, physical properties, elastic properties, flaw size distributions and concentrations, tensile/flexure strength, fracture toughness, spherical indentation and hardness, transmission electron microscopy, striae, high pressure responses via diamond anvil cell testing, laser shock differences, andmore » internal porosity were examined. Differences between these two float glasses were identified for many of these properties and characteristics, and the role of three (striae, high pressures where permanent densification can initiate, and sub-micron-sized porosity) lack understanding and deserve further attention. Lastly, the contributing roles of any of those properties or characteristics to triaxial or ballistic loading responses are not definitive; however, they provide potential correlations that may lead to improved understanding and management of loading responses in glasses used in transparent protective systems.« less

  2. Biomechanics of knee joint — A review

    NASA Astrophysics Data System (ADS)

    Madeti, Bhaskar Kumar; Chalamalasetti, Srinivasa Rao; Bolla Pragada, S. K. Sundara siva rao

    2015-06-01

    The present paper is to know how the work is carried out in the field of biomechanics of knee. Various model formulations are discussed and further classified into mathematical model, two-dimensional model and three-dimensional model. Knee geometry is a crucial part of human body movement, in which how various views of knee is shown in different planes and how the forces act on tibia and femur are studied. It leads to know the forces acting on the knee joint. Experimental studies of knee geometry and forces acting on knee shown by various researchers have been discussed, and comparisons of results are made. In addition, static and dynamic analysis of knee has been also discussed respectively to some extent.

  3. Immediate effect of Masai Barefoot Technology shoes on knee joint moments in women with knee osteoarthritis.

    PubMed

    Tateuchi, Hiroshige; Taniguchi, Masashi; Takagi, Yui; Goto, Yusuke; Otsuka, Naoki; Koyama, Yumiko; Kobayashi, Masashi; Ichihashi, Noriaki

    2014-01-01

    Footwear modification can beneficially alter knee loading in patients with knee osteoarthritis. This study evaluated the effect of Masai Barefoot Technology shoes on reductions in external knee moments in patients with knee osteoarthritis. Three-dimensional motion analysis was used to examine the effect of Masai Barefoot Technology versus control shoes on the knee adduction and flexion moments in 17 women (mean age, 63.6 years) with radiographically confirmed knee osteoarthritis. The lateral and anterior trunk lean values, knee flexion and adduction angles, and ground reaction force were also evaluated. The influence of the original walking pattern on the changes in knee moments with Masai Barefoot Technology shoes was evaluated. The knee flexion moment in early stance was significantly reduced while walking with the Masai Barefoot Technology shoes (0.25±0.14Nm/kgm) as compared with walking with control shoes (0.30±0.19 Nm/kgm); whereas the knee adduction moment showed no changes. Masai Barefoot Technology shoes did not increase compensatory lateral and anterior trunk lean. The degree of knee flexion moment in the original walking pattern with control shoes was correlated directly with its reduction when wearing Masai Barefoot Technology shoes by multiple linear regression analysis (adjusted R2=0.44, P<0.01). Masai Barefoot Technology shoes reduced the knee flexion moment during walking without increasing the compensatory trunk lean and may therefore reduce external knee loading in women with knee osteoarthritis.

  4. Snowboard traumatology: an epidemiological study.

    PubMed

    Pigozzi, F; Santori, N; Di Salvo, V; Parisi, A; Di-Luigi, L

    1997-06-01

    In the past 10 years, snowboarding has become a popular winter sport among young people, and the number of accidents has increased proportionately. The incidence of traumas from snowboarding is shown to be 4 to 6 for every 1000 medical examinations, which is similar to that of downhill skiing. However, other important statistical differences exist between the two sports. This study of 106 snowboarding-related injury cases analyzes the epidemiology of these injuries in Italy. Results found that 45.1% of injuries are located in the upper limbs and that significant advantages are obtained with the introduction of guards to protect the upper limbs during descent. Serious ligament injuries to the knee are more rare in snowboarding than in downhill skiing. In both sports, injuries are more common with rigid boots, which lead to a higher incidence of injury to the upper limbs. Finally, a high percentage of injury to beginners was found in this study. Training courses for those who are considering taking up the sport of snowboarding could significantly lower their risk of trauma.

  5. The Meniscus-Deficient Knee

    PubMed Central

    Rao, Allison J.; Erickson, Brandon J.; Cvetanovich, Gregory L.; Yanke, Adam B.; Bach, Bernard R.; Cole, Brian J.

    2015-01-01

    Meniscal tears are the most common knee injury, and partial meniscectomies are the most common orthopaedic surgical procedure. The injured meniscus has an impaired ability to distribute load and resist tibial translation. Partial or complete loss of the meniscus promotes early development of chondromalacia and osteoarthritis. The primary goal of treatment for meniscus-deficient knees is to provide symptomatic relief, ideally to delay advanced joint space narrowing, and ultimately, joint replacement. Surgical treatments, including meniscal allograft transplantation (MAT), high tibial osteotomy (HTO), and distal femoral osteotomy (DFO), are options that attempt to decrease the loads on the articular cartilage of the meniscus-deficient compartment by replacing meniscal tissue or altering joint alignment. Clinical and biomechanical studies have reported promising outcomes for MAT, HTO, and DFO in the postmeniscectomized knee. These procedures can be performed alone or in conjunction with ligament reconstruction or chondral procedures (reparative, restorative, or reconstructive) to optimize stability and longevity of the knee. Complications can include fracture, nonunion, patella baja, compartment syndrome, infection, and deep venous thrombosis. MAT, HTO, and DFO are effective options for young patients suffering from pain and functional limitations secondary to meniscal deficiency. PMID:26779547

  6. Phaeohyphomycosis infection in the knee.

    PubMed

    Sadigursky, David; Nogueira E Ferreira, Luisa; Moreno de Oliveira Corrêa, Liz

    2016-01-01

    Phaeohyphomycosis is caused by cutaneous fungi and rarely affects large joints. This is a case report on phaeohyphomycosis in the left knee of an elderly individual without immunosuppression. It was accompanied by pain and swelling the anterior knee. The case was first suspected to be suprapatellar bursitis, and was treated with nonsteroidal anti-inflammatory drugs, without remission of symptoms. Surgical treatment was performed, with resection of the suprapatellar bursa and anterior region of the quadriceps tendon. The material was sent for anatomopathological examination and culturing. The pathological examination showed phaeohyphomycosis. The treatment instituted consisted of itraconazole, 200 mg/day for six weeks, and complete remission of symptoms was achieved. The physical examination remained normal after one year of follow-up. This is the first published case of phaeohyphomycosis infection in the suprapatellar region of the knee. Although almost all the cases reported have been associated with immunosuppressed patients, this was an exception. It is important to suspect phaeohyphomycosis in cases of knee infection, in the area of the suprapatellar bursa, when the symptoms do not resolve after clinical treatment.

  7. Float processing of high-temperature complex silicate glasses and float baths used for same

    NASA Technical Reports Server (NTRS)

    Cooper, Reid Franklin (Inventor); Cook, Glen Bennett (Inventor)

    2000-01-01

    A float glass process for production of high melting temperature glasses utilizes a binary metal alloy bath having the combined properties of a low melting point, low reactivity with oxygen, low vapor pressure, and minimal reactivity with the silicate glasses being formed. The metal alloy of the float medium is exothermic with a solvent metal that does not readily form an oxide. The vapor pressure of both components in the alloy is low enough to prevent deleterious vapor deposition, and there is minimal chemical and interdiffusive interaction of either component with silicate glasses under the float processing conditions. Alloys having the desired combination of properties include compositions in which gold, silver or copper is the solvent metal and silicon, germanium or tin is the solute, preferably in eutectic or near-eutectic compositions.

  8. Floating Oil-Spill Containment Device

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    2012-01-01

    Previous oil containment booms have an open top that allows natural gas to escape, and have significant oil leakage due to wave action. Also, a subsea pyramid oil trap exists, but cannot move relative to moving oil plumes from deepsea oil leaks. The solution is to have large, moveable oil traps. One version floats on the sea surface and has a flexible tarp cover and a lower weighted skirt to completely entrap the floating oil and natural gas. The device must have at least three sides with boats pulling at each apex, and sonar or other system to track the slowly moving oil plume, so that the boats can properly locate the booms. The oil trap device must also have a means for removal of the oil and the natural gas. A second design version has a flexible pyramid cover that is attached by lines to ballast on the ocean floor. This is similar to fixed, metal pyramid oil capture devices in the Santa Barbara Channel off the coast of California. The ballast lines for the improved design, however, would have winches that can move the pyramid to always be located above the oil and gas plume. A third design is a combination of the first two. It uses a submerged pyramid to trap oil, but has no anchor and uses boats to locate the trap. It has ballast weights located along the bottom of the tarp and/or at the corners of the trap. The improved floating oil-spill containment device has a large floating boom and weighted skirt surrounding the oil and gas entrapment area. The device is triangular (or more than three sides) and has a flexible tarp cover with a raised gas vent area. Boats pull on the apex of the triangles to maintain tension and to allow the device to move to optimum locations to trap oil and gas. The gas is retrieved from a higher buoyant part of the tarp, and oil is retrieved from the floating oil layer contained in the device. These devices can be operated in relatively severe weather, since waves will break over the devices without causing oil leaking. Also, natural

  9. Dynamic splinting for knee flexion contracture following total knee arthroplasty: a case report.

    PubMed

    Finger, Eric; Willis, F Buck

    2008-12-29

    Total Knee Arthroplasty operations are increasing in frequency, and knee flexion contracture is a common pathology, both pre-existing and post-operative. A 61-year-old male presented with knee flexion contracture following a total knee arthroplasty. Physical therapy alone did not fully reduce the contracture and dynamic splinting was then prescribed for daily low-load, prolonged-duration stretch. After 28 physical therapy sessions, the active range of motion improved from -20 degrees to -12 degrees (stiff knee still lacking full extension), and after eight additional weeks with nightly wear of dynamic splint, the patient regained full knee extension, (active extension improved from -12 degrees to 0 degrees ).

  10. Posterior femoral condylar offset after total knee replacement in the risk of knee flexion contracture.

    PubMed

    Onodera, Tomohiro; Majima, Tokifumi; Nishiike, Osamu; Kasahara, Yasuhiko; Takahashi, Daisuke

    2013-08-01

    The aim of this study was to clarify the risk of knee flexion contracture associated with a posterior femoral condylar offset after total knee replacement (TKR). Radiographs from 100 healthy Japanese volunteers were included in the study. We evaluated femoral component posterior offset in various implants and compared them with the normal Japanese knee. Posterior offset of the femoral condyle is up to a maximum of 4.7 times greater than that of the healthy Japanese knee in all knee implants. Excess posterior offset of the femoral condyle in TKR prostheses may cause knee joint flexion contracture due to the relative shortening of the posterior soft tissue.

  11. Electron Temperature Measurement by Floating Probe Method Using AC Voltage

    NASA Astrophysics Data System (ADS)

    Satoshi, Nodomi; Shuichi, Sato; Mikio, Ohuchi

    2016-11-01

    This study presents a novel floating probe method to measure electron temperatures using a hollow cathode-type discharge tube. The proposed method detects a shift in the floating potential when an AC voltage is applied to a probe through an intermediary blocking capacitor. The shift in the floating potential is described as a function of the electron temperature and the applied AC voltage. The floating probe method is simpler than the Langmuir probe method because it does not require the measurement of volt-ampere characteristics. As the input AC voltage increases, the electron temperature converges. The electron temperature measured using the floating probe method with an applied sinusoidal voltage shows a value close to the first (tail) electron temperature in the range of the floating potential.

  12. Tank Tests of Two Floats for High-speed Seaplanes

    NASA Technical Reports Server (NTRS)

    Bell, Joe W

    1933-01-01

    At the request of the Bureau of Aeronautics, Navy Department, a study of the design of floats especially suitable for use on high-speed seaplanes was undertaken in the N.A.C.A. tank. This note give the results obtained in tests of one-quarter full-size models of two floats for high-speed seaplanes. One was a float similar to that used on the Macchi high-speed seaplane which competed in the 1926 Schneider Trophy races, and the other a float designed at the N.A.C.A. tank in an attempt to improve on the water performance of the Macchi float. The model of the latter showed considerably better water performance than the model of the Macchi float.

  13. When chromatin organisation floats astray: the Srcap gene and Floating-Harbor syndrome.

    PubMed

    Messina, Giovanni; Atterrato, Maria Teresa; Dimitri, Patrizio

    2016-12-01

    Floating-Harbor syndrome (FHS) is a rare human disease characterised by delayed bone mineralisation and growth deficiency, often associated with mental retardation and skeletal and craniofacial abnormalities. FHS was first described at Boston's Floating Hospital 42 years ago, but the causative gene, called Srcap, was identified only recently. Truncated SRCAP protein variants have been implicated in the mechanism of FHS, but the molecular bases underlying the disease must still be elucidated and investigating the molecular defects leading to the onset of FHS remains a challenge. Here we comprehensively review recent work and provide alterative hypotheses to explain how the Srcap truncating mutations lead to the onset of FHS.

  14. A Formalization of Floating Point Numeric Base Conversion

    DTIC Science & Technology

    The process of converting arbitrary real numbers into a floating point format is formalized as a mapping of the reals into a specified subset of real...numbers. The structure of this subset, the set of a significant digit base beta floating point numbers, is analyzed and properties of conversion...implications of these results with regards to establishing goals and standards for floating point formats and conversion procedures are considered.

  15. Trident: An FPGA Compiler Framework for Floating-Point Algorithms.

    SciTech Connect

    Tripp J. L.; Peterson, K. D.; Poznanovic, J. D.; Ahrens, C. M.; Gokhale, M.

    2005-01-01

    Trident is a compiler for floating point algorithms written in C, producing circuits in reconfigurable logic that exploit the parallelism available in the input description. Trident automatically extracts parallelism and pipelines loop bodies using conventional compiler optimizations and scheduling techniques. Trident also provides an open framework for experimentation, analysis, and optimization of floating point algorithms on FPGAs and the flexibility to easily integrate custom floating point libraries.

  16. An Analysis of the Full-Floating Journal Bearing

    NASA Technical Reports Server (NTRS)

    Shaw, M C; Nussdorfer, T J , Jr

    1947-01-01

    An analysis of the operating characteristics of a full-floating journal bearing, a bearing in which a floating sleeve is located between the journal and bearing surfaces, is presented together with charts from which the performance of such bearings may be predicted. Examples are presented to illustrate the use of these charts and a limited number of experiments conducted upon a glass full-floating bearing are reported to verify some results of the analysis.

  17. Environment parameters and basic functions for floating-point computation

    NASA Technical Reports Server (NTRS)

    Brown, W. S.; Feldman, S. I.

    1978-01-01

    A language-independent proposal for environment parameters and basic functions for floating-point computation is presented. Basic functions are proposed to analyze, synthesize, and scale floating-point numbers. The model provides a small set of parameters and a small set of axioms along with sharp measures of roundoff error. The parameters and functions can be used to write portable and robust codes that deal intimately with the floating-point representation. Subject to underflow and overflow constraints, a number can be scaled by a power of the floating-point radix inexpensively and without loss of precision. A specific representation for FORTRAN is included.

  18. Surface Drift of RAFOS Floats in the California Current System

    NASA Astrophysics Data System (ADS)

    Gates, D. C.; Collins, C. A.; Margolina, T.

    2011-12-01

    The patterns of surface drift of ninety RAFOS floats in the California Current System have been studied. The floats were launched in the California Undercurrent during 1992-2010 and were tracked by the ARGOS system when they surfaced at the end of their subsurface mission. The float hulls were glass cylinders which were 8.6 cm wide by 1.52 m long and floated with the upper 30 cm of the hull above water. The surface drift of these floats was typically equatorward in the California Current. However, some floats would flow poleward, others would drift westward into the North Pacific Gyre, and others with orbital cyclonic and/or anti-cyclonic motions. The duration of surface trajectories varied from as short as a period of days to approximately ten months. Forces on the floats included wind stress on the exposed hull and the drag of ocean currents on the subsurface hull. The latter included the Stokes drift associated with surface wind waves, Ekman flow caused by the stress of the wind on the ocean surface, and the currents associated with the general circulation of the ocean. Surface currents can be explained by calculating current direction and velocity from wind stress data. As a first step, the relationship between observed wind stress and the motion of the float is determined by assuming Ekman balance. Mesoscale effects, including eddies, are also considered in explaining the surface drift of the floats.

  19. Meta-epidemiology.

    PubMed

    Bae, Jong-Myon

    2014-01-01

    The concept of meta-epidemiology has been introduced with considering the methodological limitations of systematic review for intervention trials. The paradigm of meta-epidemiology has shifted from a statistical method into a new methodology to close gaps between evidence and practice. Main interest of meta-epidemiology is to control potential biases in previous quantitative systematic reviews and draw appropriate evidences for establishing evidence-base guidelines. Nowadays, the network meta-epidemiology was suggested in order to overcome some limitations of meta-epidemiology. To activate meta-epidemiologic studies, implementation of tools for risk of bias and reporting guidelines such as the Consolidated Standards for Reporting Trials (CONSORT) should be done.

  20. 40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... float glass manufacturing subcategory. 426.50 Section 426.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Float Glass Manufacturing Subcategory § 426.50 Applicability; description of the float...

  1. 40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... float glass manufacturing subcategory. 426.50 Section 426.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Float Glass Manufacturing Subcategory § 426.50 Applicability; description of the float...

  2. An integrated circuit floating point accumulator

    NASA Technical Reports Server (NTRS)

    Goldsmith, T. C.

    1977-01-01

    Goddard Space Flight Center has developed a large scale integrated circuit (type 623) which can perform pulse counting, storage, floating point compression, and serial transmission, using a single monolithic device. Counts of 27 or 19 bits can be converted to transmitted values of 12 or 8 bits respectively. Use of the 623 has resulted in substantial savaings in weight, volume, and dollar resources on at least 11 scientific instruments to be flown on 4 NASA spacecraft. The design, construction, and application of the 623 are described.

  3. Rounding in redundant digit floating point system

    NASA Astrophysics Data System (ADS)

    Fahmy, Hossam A. H.; Flynn, Michael J.

    2003-12-01

    Redundant representations are used to increase the performance of arithmetic units. If redundancy is eliminated, the bits needed to represent a number may increase or decrease depending on the type of redundancy used. In such a redundant representation, finding the exact location and correct decision for rounding without eliminating the redundancy or loosing its performance gains is difficult. This paper discusses the different issues related to rounding in redundant systems. It also presents a solution that was used to maintain the gains of redundancy in a floating point unit while correctly implementing the IEEE rounding modes.

  4. Localized buckling of a floating elastica.

    PubMed

    Audoly, B

    2011-07-01

    We study the buckling of a two-dimensional elastica floating on a bath of dense fluid, subjected to axial compression. The sinusoidal pattern predicted by the analysis of linear stability is shown to become localized above the buckling threshold. A nonlinear amplitude equation is derived for the envelope of the pattern. These results provide a simple interpretation to the wrinkle-to-fold transition reported by Pocivavsek et al. [Science 320, 912 (2008)]. An analogy with the classical problem of the localized buckling of a strut on a nonlinear elastic foundation is presented.

  5. Research effort aims at floating production technology

    SciTech Connect

    Not Available

    1992-08-17

    This paper reports that a 3 year research and development program on floating production systems (FPS), instigated by the Royal Norwegian Council for Scientific and Industrial Research (NTNF), has refined and qualified technologies for North Sea and arctic conditions. The FPS 2000 program, which cost 58 million kroner ($10 million), concentrated mainly on mooring systems and pipeline technology, along with new system concepts and cost reduction measures. More than 30 projects have been completed within the scheme. The anchoring and positioning project concentrates on developing methods for simulating behavior of mooring systems for large volume structures in deep water. It also seeks ways to determine efficiency of dynamic positioning thrusters under extreme conditions.

  6. Floating hydrometer with energy dissipating baffle

    SciTech Connect

    Kownurko, W.A.

    1987-11-24

    This patent describes a floating hydrometer employable for purposes of obtaining measurements of the presence of suspended solids in a fluid substance contained in a receptacle comprising: a. a probe portion operative as an instrument-bearing housing; b. an elongated tubular element having a hollow interior and at least one open end so as to enable the flow into the hollow interior of the elongated tubular element through the open end; and c. energy dissipating baffle means having a first mode of action and a second mode of action and including a member having a hollow interior.

  7. Density tracers give option to float

    SciTech Connect

    Davis, J.J.; Wood, C.J.; Lyman, G.J.

    1986-05-01

    Density tracers, that is, particles of precisely known specific gravities, offer alternative to the float-sink technique for determining separation densities. Usually made of plastic and dosed with heavy metal salts to obtain the desired specific gravity, the tracers are added to the separator feed, collected by hand from the product and reject streams, and sorted into appropriate increments on the basis of color-coding or other markings. After counting, the partition number for each specific gravity is calculated and the circuit partition or tromp curve drawn.

  8. Floating air riding seal for a turbine

    SciTech Connect

    Ebert, Todd A

    2016-08-16

    A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber formed in the stator, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, where the axial moveable annular piston includes an inlet scoop on a side opposite to the annular cavity that scoops up the swirling cooling air and directs the cooling air to the annular cavity to form an air cushion with the seal surface of the rotor.

  9. Parametric modelling of a knee joint prosthesis.

    PubMed

    Khoo, L P; Goh, J C; Chow, S L

    1993-01-01

    This paper presents an approach for the establishment of a parametric model of knee joint prosthesis. Four different sizes of a commercial prosthesis are used as an example in the study. A reverse engineering technique was employed to reconstruct the prosthesis on CATIA, a CAD (computer aided design) system. Parametric models were established as a result of the analysis. Using the parametric model established and the knee data obtained from a clinical study on 21 pairs of cadaveric Asian knees, the development of a prototype prosthesis that suits a patient with a very small knee joint is presented. However, it was found that modification to certain parameters may be inevitable due to the uniqueness of the Asian knee. An avenue for rapid modelling and eventually economical production of a customized knee joint prosthesis for patients is proposed and discussed.

  10. Adjustable hinge permits movement of knee in plaster cast

    NASA Technical Reports Server (NTRS)

    Maley, W. E.

    1967-01-01

    Metal knee hinge with an adjustable sleeve worn on the outside of a leg cast facilitates movement of the knee joint. This helps eliminate stiffness of the knee and eliminates bulkiness and adjustment difficulty.

  11. Sonography of the knee joint☆

    PubMed Central

    Razek, A.A.K.A.; Fouda, N.S.; Elmetwaley, N.; Elbogdady, E.

    2009-01-01

    The aim of this article is to review the sonographic appearances of common disorders involving the knee joint. Ultrasound is a sensitive method for diagnosis of tendon injuries. Injured ligaments appear swollen with mixed echogenicity. Meniscal injuries and muscle tears can be easily diagnosed. Ultrasound shows synovial thickening and effusion in inflammatory arthropathy and erosions of the articular surface in degenerative arthritis. It can be used effectively in the detection of rheumatoid arthritic activity and for grading degenerative arthritis lesions. Cystic lesions, as well as benign and malignant soft-tissue masses, are clearly delineated. Ultrasound is a safe noninvasive imaging modality that can be used for diagnosis of different disorders involving the knee joint. PMID:23397073

  12. MRI of anterior knee pain.

    PubMed

    Samim, Mohammad; Smitaman, Edward; Lawrence, David; Moukaddam, Hicham

    2014-07-01

    Anterior knee pain is the most common knee complaint. It may be due to a variety of soft tissue or osseous abnormalities. Knowledge of the radiologic appearance of the abnormalities allows more accurate diagnosis of the cause of the pain including chondral abnormalities, patellar instability and dislocation, femoral trochlear dysplasia, abnormal patellar location, bipartite patella, various tendinopathies, bursal inflammation, traction apophysitis in pediatric and adolescent patients, and miscellaneous diseases including mediopatellar plica syndrome and Hoffa's disease. Radiographs are often obtained to exclude acute osseous abnormalities, such as fractures. Magnetic resonance (MR) imaging offers superior soft tissue contrast resolution and allows for more accurate evaluation of the underlying etiology and therefore may improve treatment and possible surgical planning.

  13. [Molecular epidemiology in the epidemiological transition].

    PubMed

    Tapia-Conyer, R

    1997-01-01

    The epidemiological transition describes the changes in the health profile of populations where infectious diseases are substituted by chronic or non-communicable diseases. Even in industrialized countries, infectious diseases emerge as important public health problems and with a very important association with several type of neoplasm. Molecular epidemiology brings in new tools for the study of the epidemiological transition by discovering infectious agents as etiology of diseases, neither of both new. Much has been advanced in the understanding of the virulence and resistance mechanism of different strains, or improving the knowledge on transmission dynamics and dissemination pathways of infectious diseases. As to the non-communicable diseases, molecular epidemiology has enhanced the identification of endogenous risk factors link to alterations, molecular changes in genetic material, that will allow a more detail definition of risk and the identification of individual and groups at risk of several diseases. The potential impact of molecular epidemiology in other areas as environmental, lifestyles and nutritional areas are illustrated with several examples.

  14. Normal anatomy and biomechanics of the knee.

    PubMed

    Flandry, Fred; Hommel, Gabriel

    2011-06-01

    Functionally, the knee comprises 2 articulations-the patellofemoral and tibiofemoral. Stability of the joint is governed by a combination of static ligaments, dynamic muscular forces, meniscocapsular aponeurosis, bony topography, and joint load. The surgeon is ill equipped to undertake surgical treatment of a dislocated knee without a sound footing in the anatomic complexities of this joint. We review the normal anatomy of the knee, emphasizing connective tissue structures and common injury patterns.

  15. A prosthetic knee using magnetorhelogical fluid damper for above-knee amputees

    NASA Astrophysics Data System (ADS)

    Park, Jinhyuk; Choi, Seung-Bok

    2015-04-01

    A prosthetic knee for above-knee (AK) amputees is categorized into two types; namely a passive and an active type. The passive prosthetic knee is generally made by elastic materials such as carbon fiber reinforced composite material, titanium and etc. The passive prosthetic knee easy to walk. But, it has disadvantages such that a knee joint motion is not similar to ordinary people. On the other hand, the active prosthetic knee can control the knee joint angle effectively because of mechanical actuator and microprocessor. The actuator should generate large damping force to support the weight of human body. But, generating the large torque using small actuator is difficult. To solve this problem, a semi-active type prosthetic knee has been researched. This paper proposes a semi-active prosthetic knee using a flow mode magneto-rheological (MR) damper for AK amputees. The proposed semi-active type prosthetic knee consists of the flow mode MR damper, hinge and prosthetic knee body. In order to support weight of human body, the required energy of MR damper is smaller than actuator of active prosthetic leg. And it can control the knee joint angle by inducing the magnetic field during the stance phase.

  16. Instability following total knee arthroplasty.

    PubMed

    Rodriguez-Merchan, E Carlos

    2011-10-01

    Background Knee prosthesis instability (KPI) is a frequent cause of failure of total knee arthroplasty. Moreover, the degree of constraint required to achieve immediate and long-term stability in total knee arthroplasty (TKA) is frequently debated. Questions This review aims to define the problem, analyze risk factors, and review strategies for prevention and treatment of KPI. Methods A PubMed (MEDLINE) search of the years 2000 to 2010 was performed using two key words: TKA and instability. One hundred and sixty-five initial articles were identified. The most important (17) articles as judged by the author were selected for this review. The main criteria for selection were that the articles addressed and provided solutions to the diagnosis and treatment of KPI. Results Patient-related risk factors predisposing to post-operative instability include deformity requiring a large surgical correction and aggressive ligament release, general or regional neuromuscular pathology, and hip or foot deformities. KPI can be prevented in most cases with appropriate selection of implants and good surgical technique. When ligament instability is anticipated post-operatively, the need for implants with a greater degree of constraint should be anticipated. In patients without significant varus or valgus malalignment and without significant flexion contracture, the posterior cruciate ligament (PCL) can be retained. However, the PCL should be sacrificed when deformity exists particularly in patients with rheumatoid arthritis, previous patellectomy, previous high tibial osteotomy or distal femoral osteotomy, and posttraumatic osteoarthritis with disruption of the PCL. In most cases, KPI requires revision surgery. Successful outcomes can only be obtained if the cause of KPI is identified and addressed. Conclusions Instability following TKA is a common cause of the need for revision. Typically, knees with deformity, rheumatoid arthritis, previous patellectomy or high tibial osteotomy, and

  17. The Swedish Knee Arthroplasty Register

    PubMed Central

    Robertsson, O.; Ranstam, J.; Sundberg, M.; W-Dahl, A.; Lidgren, L.

    2014-01-01

    We are entering a new era with governmental bodies taking an increasingly guiding role, gaining control of registries, demanding direct access with release of open public information for quality comparisons between hospitals. This review is written by physicians and scientists who have worked with the Swedish Knee Arthroplasty Register (SKAR) periodically since it began. It reviews the history of the register and describes the methods used and lessons learned. Cite this article: Bone Joint Res 2014;3:217–22. PMID:24986492

  18. Hinge total knee replacement revisited

    PubMed Central

    Cameron, Hugh U.; Hu, Cungen; Vyamont, Didier

    1997-01-01

    Objective To determine if aseptic loosening is a major problem in hinge total knee replacement. Design A cohort study. Setting A university-affiliated institute, specializing in elective orthopedic surgery. Patients Fifty-eight patients, mainly those requiring revision, in whom the conditions were such that it was felt only a totally constrained implant was appropriate. In 7 patients the implant was press-fitted; in the remainder it was cemented. Five patients required fusion or revision, and 8 died less than 2 years after implantation, leaving 45 for review. Follow-up was 2 to 13 years. Intervention Total knee replacement with a Guepar II prosthesis. Main outcome measures Radiolucency determined by the Cameron system and clinical scoring using the Hospital for Special Surgery system. Results Of the cemented components, 91% of femoral stems were type IA (no lucency), 9% were type IB (partial lucency), with no type II or III lucency. Tibial lucency was 87% type IA and 13% type IB, with no type II or III lucency. Of the noncemented components, 58% of femoral components were type IA and 42% type IB. Tibial lucency was 71% type IA and 29% type IB. Lucency was mainly present in zones 1 and 2 adjacent to the knee. Clinical rating was 18% excellent, 20% good, 20% fair and 42% poor. Postoperative complications included infection (13%), aseptic loosening (7%), quadriceps lag (16%) and extensor mechanism problems (16%). Conclusions Aseptic loosening is an uncommon problem in hinge total knee replacement. The complication rate in cases of sufficient severity as to require a hinge replacement remains high. Current indications for a hinge prosthesis are anteroposterior instability with a very large flexion gap, complete absence of the collateral ligaments and complete absence of a functioning extensor mechanism. PMID:9267296

  19. Bursae around the knee joints

    PubMed Central

    Chatra, Priyank S

    2012-01-01

    A bursa is a fluid-filled structure that is present between the skin and tendon or tendon and bone. The main function of a bursa is to reduce friction between adjacent moving structures. Bursae around the knee can be classified as those around the patella and those that occur elsewhere. In this pictorial essay we describe the most commonly encountered lesions and their MRI appearance. PMID:22623812

  20. Painful knee prosthesis: surgical approach

    PubMed Central

    Villano, Marco; Carulli, Christian; Puccini, Serena; Soderi, Stefano; Innocenti, Massimo

    2011-01-01

    Summary There are many conditions that may be responsible of a painful knee prosthesis. The possible causes are not always easily diagnosed. Common causes of prosthetic failure, such as aseptic loosening, infection, instability, progressive patellar arthropathy and recurrent synovitis are associated with clearly defined radiographic and/or clinical evidence. Prosthetic infection should always be considered first until any other cause has been demonstrated. In the presence of an infected prosthesis we carry out a two-step revision. Aseptic loosening needs implant revision more often with increasing prosthesis stability. Varus-valgus, anteroposterior, global and patello-femoral instability are failures often due to technical errors; superstabilized or constrained implants are needed depending on the instability entity. In presence of patello-femoral pain it is necessary to evaluate the stability of the patellar component and any alterations in its motion. Patellar progressive arthropathy can often cause late-onset knee pain; in this case patella resurfacing is needed. Altered patellar tracking, may need a lateral release but in some cases is related to misalignment of the components and the revision procedure is mandatory. Nevertheless, the diagnosis and treatment of a painful knee prosthesis can be extremely difficult if there is no clear evidence of any of the most common causes of failure. Referred pain, ligament and tendon dysfunction, cutaneous neuromas, synovitis, a patellar clunk have to be diagnosed and treated. A possible aetiological understimated factor is painful knee prosthesis due to metals sensibilization, in particular to nickel. In this event the quantity of nickel in the revision prosthesis must be minimal. PMID:22461812

  1. Imaging following acute knee trauma.

    PubMed

    Kijowski, R; Roemer, F; Englund, M; Tiderius, C J; Swärd, P; Frobell, R B

    2014-10-01

    Joint injury has been recognized as a potent risk factor for the onset of osteoarthritis. The vast majority of studies using imaging technology for longitudinal assessment of patients following joint injury have focused on the injured knee joint, specifically in patients with anterior cruciate ligament injury and meniscus tears where a high risk for rapid onset of post-traumatic osteoarthritis is well known. Although there are many imaging modalities under constant development, magnetic resonance (MR) imaging is the most important instrument for longitudinal monitoring after joint injury. MR imaging is sensitive for detecting early cartilage degeneration and can evaluate other joint structures including the menisci, bone marrow, tendons, and ligaments which can be sources of pain following acute injury. In this review, focusing on imaging following acute knee trauma, several studies were identified with promising short-term results of osseous and soft tissue changes after joint injury. However, studies connecting these promising short-term results to the development of osteoarthritis were limited which is likely due to the long follow-up periods needed to document the radiographic and clinical onset of the disease. Thus, it is recommended that additional high quality longitudinal studies with extended follow-up periods be performed to further investigate the long-term consequences of the early osseous and soft tissue changes identified on MR imaging after acute knee trauma.

  2. Cryotherapy impairs knee joint position sense.

    PubMed

    Oliveira, R; Ribeiro, F; Oliveira, J

    2010-03-01

    The effects of cryotherapy on joint position sense are not clearly established; however it is paramount to understand its impact on peripheral feedback to ascertain the safety of using ice therapy before resuming exercise on sports or rehabilitation settings. Thus, the aim of the present study was to determine the effects of cryotherapy, when applied over the quadriceps and over the knee joint, on knee position sense. This within-subjects repeated-measures study encompassed fifteen subjects. Knee position sense was measured by open kinetic chain technique and active positioning at baseline and after cryotherapy application. Knee angles were determined by computer analysis of the videotape images. Twenty-minute ice bag application was applied randomly, in two sessions 48 h apart, over the quadriceps and the knee joint. The main effect for cryotherapy application was significant (F (1.14)=7.7, p=0.015) indicating an increase in both absolute and relative angular errors after the application. There was no significant main effect for the location of cryotherapy application, indicating no differences between the application over the quadriceps and the knee joint. In conclusion, cryotherapy impairs knee joint position sense in normal knees. This deleterious effect is similar when cryotherapy is applied over the quadriceps or the knee joint.

  3. Surgery for osteoarthritis of the knee.

    PubMed

    Richmond, John C

    2013-02-01

    Although total knee replacement is an excellent treatment of end-stage osteoarthritis of the knee in the older (>65 years) population, many patients with less severe disease are significantly impacted by their symptoms and have failed to respond to less invasive treatment alternatives. For this group, there are several less invasive surgical alternatives, including arthroscopic meniscectomy, grafting of symptomatic areas of bone marrow lesions, unloading osteotomy, and unicompartmental knee replacement. Current total knee arthroplasty designs can be expected to survive 20 years or more in the older, less active population. New materials may extend that survivorship.

  4. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... The resultant water load must be applied in the plane of symmetry of the float at a point three... r y=ratio of the lateral distance between the center of gravity and the plane of symmetry of the... the plane of symmetry of the float at a point one-fourth of the distance from the bow to the step...

  5. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... The resultant water load must be applied in the plane of symmetry of the float at a point three... r y=ratio of the lateral distance between the center of gravity and the plane of symmetry of the... the plane of symmetry of the float at a point one-fourth of the distance from the bow to the step...

  6. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... The resultant water load must be applied in the plane of symmetry of the float at a point three... r y=ratio of the lateral distance between the center of gravity and the plane of symmetry of the... the plane of symmetry of the float at a point one-fourth of the distance from the bow to the step...

  7. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... The resultant water load must be applied in the plane of symmetry of the float at a point three... r y=ratio of the lateral distance between the center of gravity and the plane of symmetry of the... the plane of symmetry of the float at a point one-fourth of the distance from the bow to the step...

  8. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... The resultant water load must be applied in the plane of symmetry of the float at a point three... r y=ratio of the lateral distance between the center of gravity and the plane of symmetry of the... the plane of symmetry of the float at a point one-fourth of the distance from the bow to the step...

  9. ROUND-OFF ERROR OF FLOATING-POINT DIGITAL FILTERS,

    DTIC Science & Technology

    the filter, the problem has been studied extensively. The only result available for floating - point arithmetic realization of digital filters is an...paper, a statistic approach is adopted to treat the round-off error problem for floating - point computer realization of filters. (Author)

  10. Algorithms to Reveal Properties of Floating-Point Arithmetic

    DTIC Science & Technology

    Two algorithms are presented in the form of Fortran subroutines. Each subroutine computes the radix and number of digits of the floating - point numbers...and whether rounding or chopping is done by the machine on which it is run. The methods are shown to work on any ’reasonable’ floating - point computer.

  11. 40 CFR 63.1043 - Standards-Separator floating roof.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) National Emission Standards for Oil-Water Separators and Organic-Water Separators § 63.1043 Standards... controlling air emissions from an oil-water separator or organic-water separator using a floating roof. (b... floating roof shall be equipped with two continuous seals, one above the other, between the wall of...

  12. 22. Float located adjacent to entry stair in filtration bed. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  13. 33 CFR 143.120 - Floating OCS facilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Floating OCS facilities. 143.120 Section 143.120 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES DESIGN AND EQUIPMENT OCS Facilities § 143.120 Floating OCS...

  14. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Life floats. 144.01-1 Section 144.01-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each...

  15. 14 CFR 23.535 - Auxiliary float loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.535 Auxiliary float loads. (a) General. Auxiliary floats and their attachments and supporting structures must be designed for the conditions prescribed in this section. In the cases specified...

  16. 14 CFR 23.535 - Auxiliary float loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.535 Auxiliary float loads. (a) General. Auxiliary floats and their attachments and supporting structures must be designed for the conditions prescribed in this section. In the cases specified...

  17. 14 CFR 23.535 - Auxiliary float loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.535 Auxiliary float loads. (a) General. Auxiliary floats and their attachments and supporting structures must be designed for the conditions prescribed in this section. In the cases specified...

  18. 14 CFR 23.535 - Auxiliary float loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.535 Auxiliary float loads. (a) General. Auxiliary floats and their attachments and supporting structures must be designed for the conditions prescribed in this section. In the cases specified...

  19. 14 CFR 23.535 - Auxiliary float loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.535 Auxiliary float loads. (a) General. Auxiliary floats and their attachments and supporting structures must be designed for the conditions prescribed in this section. In the cases specified...

  20. 14 CFR 29.751 - Main float buoyancy.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight of the rotorcraft...

  1. 14 CFR 25.751 - Main float buoyancy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float buoyancy. 25.751 Section 25.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... buoyancy. Each main float must have— (a) A buoyancy of 80 percent in excess of that required to support...

  2. 14 CFR 25.751 - Main float buoyancy.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Main float buoyancy. 25.751 Section 25.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... buoyancy. Each main float must have— (a) A buoyancy of 80 percent in excess of that required to support...

  3. 14 CFR 29.751 - Main float buoyancy.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight of the rotorcraft...

  4. 14 CFR 29.751 - Main float buoyancy.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight of the rotorcraft...

  5. 14 CFR 29.751 - Main float buoyancy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight of the rotorcraft...

  6. 14 CFR 29.751 - Main float buoyancy.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... buoyancy. (a) For main floats, the buoyancy necessary to support the maximum weight of the rotorcraft...

  7. 14 CFR 25.751 - Main float buoyancy.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float buoyancy. 25.751 Section 25.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... buoyancy. Each main float must have— (a) A buoyancy of 80 percent in excess of that required to support...

  8. 14 CFR 25.751 - Main float buoyancy.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Main float buoyancy. 25.751 Section 25.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... buoyancy. Each main float must have— (a) A buoyancy of 80 percent in excess of that required to support...

  9. 14 CFR 25.751 - Main float buoyancy.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Main float buoyancy. 25.751 Section 25.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... buoyancy. Each main float must have— (a) A buoyancy of 80 percent in excess of that required to support...

  10. Evaporation mitigation using floating modular devices

    NASA Astrophysics Data System (ADS)

    Hassan, M. Mahmudul; Peirson, William Leslie; Neyland, Bryce M.; Fiddis, Nicholas McQuistan

    2015-11-01

    Reducing evaporation losses from open water storages is of paramount importance in the improvement of water security in arid countries, including Australia. Widespread adoption of evaporation mitigation techniques has been prevented by their high capital and maintenance or operating costs. The use of clean, floating recycled materials to mitigate evaporation technique has been investigated systematically at sites within both the coastal and semi-arid zones of Australia. Evaporation reduction systematically increases with the proportion of covered surface. Evaporation is reduced by 43% at coastal site and 37% at arid zone site at the maximum packing densities achievable for a single layer of floating devices. The study highlights the importance of both long-term investigations and the climatic influences in the robust quantification of evaporation mitigation. The effects of solar radiation, temperature, wind speed and relative humidity on the evaporation rate at both study sites have been determined in terms of both the classical Penman model and FAO Penman Monteith model with corresponding pan coefficients quantified. FAO Penman Monteith model better estimates evaporation from the open reference tank.

  11. Evaporation mitigation by floating modular devices

    NASA Astrophysics Data System (ADS)

    Hassan, M. M.; Peirson, W. L.

    2016-05-01

    Prolonged periods of drought and consequent evaporation from open water bodies in arid parts of Australia continue to be a threat to water availability for agricultural production. Over many parts of Australia, the annual average evaporation exceeds the annual precipitation by more than 5 times. Given its significance, it is surprising that no evaporation mitigation technique has gained widespread adoption to date. High capital and maintenance costs of manufactured products are a significant barrier to implementation. The use of directly recycled clean plastic containers as floating modular devices to mitigate evaporation has been investigated for the first time. A six-month trial at an arid zone site in Australia of this potential cost effective solution has been undertaken. The experiment was performed using clean conventional drinking water bottles as floating modules on the open water surface of 240-L tanks with three varying degrees of covering (nil, 34% and 68%). A systematic reduction in evaporation is demonstrated during the whole study period that is approximately linearly proportional to the covered surface. These results provide a potential foundation for robust evaporation mitigation with the prospect of implementing a cost-optimal design.

  12. Water-Pressure Distribution on Seaplane Float

    NASA Technical Reports Server (NTRS)

    Thompson, F L

    1929-01-01

    The investigation presented in this report was conducted for the purpose of determining the distribution and magnitude of water pressures likely to be experienced on seaplane hulls in service. It consisted of the development and construction of apparatus for recording water pressures lasting one one-hundredth second or longer and of flight tests to determine the water pressures on a UO-1 seaplane float under various conditions of taxiing, taking off, and landing. The apparatus developed was found to operate with satisfactory accuracy and is suitable for flight tests on other seaplanes. The tests on the UO-1 showed that maximum pressures of about 6.5 pounds per square inch occur at the step for the full width of the float bottom. Proceeding forward from the step the maximum pressures decrease in magnitude uniformly toward the bow, and the region of highest pressures narrows toward the keel. Immediately abaft the step the maximum pressures are very small, but increase in magnitude toward the stern and there once reached a value of about 5 pounds per square inch. (author)

  13. A laboratory study of floating lenticular anticyclones

    NASA Astrophysics Data System (ADS)

    Le Gal, Patrice; de La Rosa, Hector; Cros, Anne; Cruz-Gomez, Raúl; Le Bars, Michael

    2014-11-01

    Oceanic vortices play an important role in the redistribution of heat, salt and momentum in the oceans. Among these vortices, floating lenses or rings are often met in the meanders of warm currents. For instance the North Brazil Current rings are among the most intense and large anticyclonic vortices on Earth. In order to better describe these vortices, we propose here a laboratory study of these floating anticyclonic lenses. A blob of fresh water is slowly injected near the surface of a rotating layer of homogeneous salted water. Because of the opposite effects of rotation that tends to generate columnar structures and density stratification that spreads light water on the surface, the vortices take a finite size three dimensionnal typical shape. Visualization and PIV measurements of the shape, aspect ratios and vorticity profiles are compared to analytical predictions that use first a simple solid body rotation model and then a more realistic isolated Gaussian vorticity field inside the anticyclones. This work was carried out within the framework of a bilateral cooperation between CNRS (France) and CONACYT (Mexico).

  14. Suppression of Marangoni Convection in Float Zones

    NASA Technical Reports Server (NTRS)

    Dressler, R. F.

    1985-01-01

    The basic purpose of this program is to demonstrate by means of an Earth-based 1-g experiment that the undesirable Marangoni (surface tension) convection can be suppressed or significantly reduced by means of gas jets directed tangentially to the free surface of the liquid in a float zone. These jets will establish the tangential shear stress field over the surface which must be adjusted to equal the counter-stress resultant of the Marangoni shear stress which causes the convection. For proposed materials processing in space (o-g), particularly of important, highly reactive semiconductor materials, e.g., silicon, microgravity will virtually eliminate the unwanted thermal-buoyancy convection in the liquid silicon, but will have no effect in reducing the Marangoni convection. Unless this can be sufficiently suppressed by other means, there may be no significant advantages to the proposed space processing of reactive semiconductors. Although some inert gas such as argon must be used for the corrosive liquid silicon, the Earth-based experiment uses air jets and various transparent oils, since the basic principle involved is the same. The first float zone is enclosed in a very small rectangular box with a quasi-planar free surface. Stable Marangoni convection has been achieved and velocities measured photographically. The air jet system with variable velocity and temperature is under construction. Three independent parameters must be optimized to attain maximum suppression: the gas velocity, angle of attack, and gas temperature.

  15. Immediate Effects of an Elastic Knee Sleeve on Frontal Plane Gait Biomechanics in Knee Osteoarthritis

    PubMed Central

    Schween, Raphael; Gehring, Dominic; Gollhofer, Albert

    2015-01-01

    Introduction Osteoarthritis of the knee affects millions of people. Elastic knee sleeves aim at relieving symptoms. While symptomatic improvements have been demonstrated as a consequence of elastic knee sleeves, evidence for biomechanical alterations only exists for the sagittal plane. We therefore asked what effect an elastic knee sleeve would have on frontal plane gait biomechanics. Methods 18 subjects (8 women, 10 men) with osteoarthritis of the medial tibiofemoral joint walked over ground with and without an elastic knee sleeve. Kinematics and forces were recorded and joint moments were calculated using an inverse dynamics approach. Conditions with sleeve and without sleeve were compared with paired t-Tests. Results With the sleeve, knee adduction angle at ground contact was reduced by 1.9±2.1° (P = 0.006). Peak knee adduction was reduced by 1.5±1.6° (P = 0.004). The first peak knee adduction moment and positive knee adduction impulse were decreased by 10.1% (0.74±0.9 Nm•kg-1; P = 0.002) and 12.9% (0.28±0.3 Nm•s•kg-1; P < 0.004), respectively. Conclusion Our study provides evidence that wearing an elastic knee sleeve during walking can reduce knee adduction angles, moments and impulse in subjects with knee osteoarthritis. As a higher knee adduction moment has previously been identified as a risk factor for disease progression in patients with medial knee osteoarthritis, we speculate that wearing a knee sleeve may be beneficial for this specific subgroup. PMID:25621488

  16. Floating-point arithmetic in embedded and reconfigurable computing systems

    NASA Astrophysics Data System (ADS)

    Gilani, Syed; Schulte, Michael; Compton, Katherine; Hockert, Neil

    2009-08-01

    Modern embedded and reconfigurable systems need to support a wide range of applications, many of which may significantly benefit from hardware support for floating-point arithmetic. Some of these applications include 3D graphics, multiple-input multiple-output (MIMO) wireless communication algorithms, orthogonal frequency division multiplexing (OFDM) based systems, and digital filters. Many of these applications have real-time constraints that cannot tolerate the high latency of software emulated floating-point arithmetic. Moreover, software emulation can lead to higher energy consumption that may be unsuitable for applications in powerconstrained environments. This paper examines applications that can potentially benefit from hardware support for floating-point arithmetic and discusses some approaches taken for floating-point arithmetic in embedded and reconfigurable systems. Precision and range analysis is performed on emerging applications in the MIMO wireless communications domain to investigate the potential for low power floating-point units that utilize reduced precision and exponent range.

  17. Hydroelastic responses of pontoon type very large floating offshore structure

    SciTech Connect

    Haeda, Hisaaki; Miyajima, Shyogo; Masuda, Koich; Ikoma, Tomoki

    1996-12-31

    The authors developed the estimating method of the hydroelastic response of a very large pontoon type floating structure. In this method, the pressure distribution method with shallow draft assumption was used to obtain the hydrodynamic forces considering the elastic motion of a floating body. The elastic responses of very large floating structure were estimated by using 1-D beam modeling. On the other hand, to observe the elastic response of a large pontoon type structure they carried out experiments in head sea and head-beam sea conditions. The experimental model was an elastic model of pontoon type large floating body. To validate numerical estimation method the authors compared the numerical results with experimental results. From these results, they found good agreement and confirmed the accuracy of this numerical estimation method of the hydroelasticity of a very large pontoon type floating structure.

  18. Floating production systems in a ``new economic regime``

    SciTech Connect

    Eriksen, K.; D`Souza, R.B.; Wilson, A.J.S.; Johansson, O.

    1995-12-31

    Except for a short period before, during and after the Gulf War, the oil prices have been depressed for 8--10 years. This has forced industry to be profitable at these low oil price levels. Since 1975 various floating production systems have been evaluated and used as field development solutions around the world. As technical challenges have been overcome, floating production systems have become leading contenders for traditional and deepwater field developments in this new economic regime. There are many types of Floating production systems. A few examples are--the semisubmersible Floating Production System (FPS), the monohull Floating Production, Storage and Offloading system (FPSO), the Spar Buoy and the Deep Draft Floater. As the FPS and FPSO represent proven technology and are leading contenders for several field developments in both the North Sea and the Gulf of Mexico, this paper will concentrate on these concepts.

  19. [Epidemiology and public policies].

    PubMed

    Barata, Rita Barradas

    2013-03-01

    The present essay deals with the relation between epidemiology and public policies, highlighting the epidemiology position in the public health field, analyzing the impact of public policies over epidemiological profile and contributions from epidemiology to the lay down, implementation and evaluation of public health policies. In the first title, the essay debates the links between the epidemiology and public health field, the social determinants and political action framework proposed by the WHO's Commission on Social Determinants of Health, and different approaches of health policies. In the second title the essay analyses the reduction of child stunting in Brazil as an example of public policies that impact epidemiological profile. The third title presents three strategic topics for the application of public health policies: reduction of social inequalities in health, health promotion and regulation of products and services that have impact over health. The fourth title discusses the possibilities and difficulties to combine the epidemiological knowledge in the lay down, implementation and evaluation of public policies and, finally, material examples of such relation between epidemiology and public policies are presented.

  20. Vaccine epidemiology: A review

    PubMed Central

    Lahariya, Chandrakant

    2016-01-01

    This review article outlines the key concepts in vaccine epidemiology, such as basic reproductive numbers, force of infection, vaccine efficacy and effectiveness, vaccine failure, herd immunity, herd effect, epidemiological shift, disease modeling, and describes the application of this knowledge both at program levels and in the practice by family physicians, epidemiologists, and pediatricians. A case has been made for increased knowledge and understanding of vaccine epidemiology among key stakeholders including policy makers, immunization program managers, public health experts, pediatricians, family physicians, and other experts/individuals involved in immunization service delivery. It has been argued that knowledge of vaccine epidemiology which is likely to benefit the society through contributions to the informed decision-making and improving vaccination coverage in the low and middle income countries (LMICs). The article ends with suggestions for the provision of systematic training and learning platforms in vaccine epidemiology to save millions of preventable deaths and improve health outcomes through life-course. PMID:27453836

  1. Unicondylar knee arthroplasty: a cementless perspective

    PubMed Central

    Forsythe, Michael E.; Englund, Roy E.; Leighton, Ross K.

    2000-01-01

    Objective To compare the results of cementless unicondylar knee arthroplasty (UKA) with those already reported in a similar study on cemented UKA. Design A case-series cross-sectional study. Setting The Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax. Patients Fifty-one patients who underwent a total of 57 UKAs between May 1989 and May 1997. Inclusion criteria were osteoarthritis involving the predominantly the medial compartment of the knee, relative sparing of the other compartments, less than 15° of varus, minimal knee instability, and attendance at the postoperative clinical visit. Intervention Cementless UKA. Main outcome measures Clinical parameters that included pain, range of motion and the Knee Society Clinical Knee Score. Roentgenographic parameters that included α, β, γ and σ angles and the presence of periprosthetic radiolucency or loose beads. Results Age, weight, gender and follow-up interval did not significantly affect the clinical results in terms of pain, range of motion or knee score. Knees with more than 1 mm of radiolucency had significantly lower knee scores than those with no radiolucency. Knees that radiologically had loose beads also had significantly lower knee scores. The clinical outcomes of cementless UKA were comparable to those already reported on cemented UKA. Cementless femurs had less radiolucency than the cemented femurs, whereas cementless tibias had more radiolucency than their cemented counterparts. Conclusions Cementless UKA seems to be as efficacious as cemented UKA. However, there is some concern about the amount of radiolucency in the cementless tibial components. A randomized clinical trial comparing both cementless and cemented tibial components with a cementless femur (hybrid knee) is needed to further assess this controversial issue in UKA. PMID:11129829

  2. [Epidemiology and heterogeny].

    PubMed

    Breilh, J; Granda, E

    1989-01-01

    The innovation of epidemiology plays a crucial role in the development of the health sciences. The authors emphasize the importance of epistemological analysis related to scientific and technical production. They focus on the theoretical and methodological contributions of the principal Latin American groups in the field of epidemiology, stating their main accomplishments, issues and potentials. When reviewing those conceptual and practical innovations, the authors analyse the effects of broader historical conditions on scientific work. To them, Latin American contemporary innovative epidemiological research and production have developed clearly differentiated principles, methods and technical projections which have led to a movement of critical or 'social' epidemiology. The functionalist approach of conventional epidemiology, characterized by an empiricist viewpoint, is being overcome by a more rigorous and analytical approach. This new epidemiological approach, in which the authors as members of CEAS (Health Research and Advisory Center) are working, has selectively incorporated some of the technical instruments of conventional epidemiology, subordinating them to a different theoretical and logical paradigm. The new framework of this group explains the need to consider the people's objective situation and necessities, when constructing scientific interpretations and planning technical action. In order to accomplish this goal, epidemiological reasoning has to reflect the unity of external epidemiological facts and associations, the so-called phenomenological aspect of health, with the underlying determinants and conditioning processes or internal relations, which are the essence of the health-disease production and distribution process. Epidemiological analysis is considered not only as a problem of empirical observation but as a process of theoretical construction, in which there is a dynamic fusion of deductive and inductive reasoning.(ABSTRACT TRUNCATED AT 250

  3. Astym® Therapy for the Management of Recalcitrant Knee Joint Stiffness after Total Knee Arthroplasty.

    PubMed

    Bhave, Anil; Corcoran, James; Cherian, Jeffery J; Mont, Michael A

    2016-01-01

    Knee stiffness is a common complication after total knee arthroplasty (TKA). Despite studies published on the surgical management of reduced range of motion (ROM) after TKA, there is limited evidence on the nonoperative management of joint and soft tissue imbalances possibly contributing to reduced knee ROM. This report assesses changes in ROM, pain, function, and patellar tendon length after Astym® joint mobilization use. A 38-year-old male professional skier had a right TKA 3 months before presentation with 2 subsequent manipulations under anesthesia secondary to persistent knee stiffness. He had patellar baja on radiograph, a reduced arc of ROM, reduced patellar mobility and muscular extensibility, and pain to palpation along the patellar tendon. He had 12 visits of physical therapy with the use of Astym®, patellar mobilization, and tibio-femoral mobilizations with movement. The patient also used a customized knee device at home for prolonged knee extension stretching. The patient was treated for 12 visits, along with home use of customized bracing for knee extension. Significant improvements were seen in pain, function, and ROM. He returned to work full-time, ambulated prolonged distances, and negotiated stairs pain-free. He also demonstrated resolution of patellar baja radiographically. Conservative management of recalcitrant knee joint stiffness after primary TKA can be effective in restoring knee mobility and reducing pain and activity limitation. A multimodal approach using Astym® treatment, customized knee bracing, and targeted joint mobilization can be effective in resolving knee joint stiffness.

  4. Total Knee Arthroplasty in Severe Unstable Knee: Case-Report and Literature Review

    PubMed Central

    Tahmasebi, Mohammad Naghi; Amjad, Gholamreza Ghorbani; Kaseb, Mohammad Hassan; Bashti, Kaveh

    2017-01-01

    Multiplanar or global laxity in arthritic knee is rare, most of this patients have neuromuscular disorder (post poliomyelitis, spinal dystrophy) or history of knee trauma. Ligament insufficiency and severe bone loss is significant in this patient. The estimated prevalence for the concurrence of charcot marie-tooth (CMT) with myasthenia gravis (MG) suggests an extremely rare event. We have presented a 54-year-old female patient with CMT and MG complaining of progressive pain, swelling, and crepitation of the knee joints who had been undergone total knee arthroplasty (TKA) with rotating hinge prosthesis. She had an acute myasthenia crisis soon after operation with prolonged intubation and intensive care unit admission. Radiographies and physical examination revealed bilateral severe unstable arthritic knee joints and left knee posterior dislocation. Short-term postoperative follow-up revealed improved knee function and resolution of all symptoms in the operated side. PMID:28271089

  5. Total Knee Arthroplasty for Severe Flexion Contracture in Rheumatoid Arthritis Knees

    PubMed Central

    Hwang, Youn Soo; Moon, Kyu Pill; Kim, Kyung Taek; Kim, Jin Wan; Park, Won Seok

    2016-01-01

    Flexion contracture deformities, as well as severe varus and valgus deformities of the knee joint, accompany osteoarthritis or rheumatoid arthritis (RA). In particular, severe flexion contracture deformity of the knee joint is often found in patients with RA, which renders them nonambulatory. This report describes a 26-year-old female patient diagnosed with RA 10 years ago. She had chronic joint pain, severe flexion contracture, valgus deformity in both knees, and limited range of motion in both knees and became nonambulatory. She underwent a total knee arthroplasty (TKA) and serial casting and physical therapy to restore stable joint movement and correct knee joint deformity. Her pain was successfully relieved, and she was able to walk after surgery. Here, we report the excellent results of TKA in this RA patient with severe flexion contracture of both knees. PMID:27894181

  6. Effect of patellar thickness on knee flexion in total knee arthroplasty: a biomechanical and experimental study.

    PubMed

    Abolghasemian, Mansour; Samiezadeh, Saeid; Sternheim, Amir; Bougherara, Habiba; Barnes, C Lowry; Backstein, David J

    2014-01-01

    A biomechanical computer-based model was developed to simulate the influence of patellar thickness on passive knee flexion after arthroplasty. Using the computer model of a single-radius, PCL-sacrificing knee prosthesis, a range of patella-implant composite thicknesses was simulated. The biomechanical model was then replicated using two cadaveric knees. A patellar-thickness range of 15 mm was applied to each of the knees. Knee flexion was found to decrease exponentially with increased patellar thickness in both the biomechanical and experimental studies. Importantly, this flexion loss followed an exponential pattern with higher patellar thicknesses in both studies. In order to avoid adverse biomechanical and functional consequences, it is recommended to restore patellar thickness to that of the native knee during total knee arthroplasty.

  7. In vivo knee kinematics in patients with bilateral total knee arthroplasty of 2 designs.

    PubMed

    Okamoto, Nobukazu; Breslauer, Leigh; Hedley, Anthony K; Mizuta, Hiroshi; Banks, Scott A

    2011-09-01

    Many younger and highly active patients desire to achieve high flexion after total knee arthroplasty. This study's purpose was to determine if a contemporary total knee arthroplasty design improved functional knee flexion compared with a traditional total knee arthroplasty in patients living a Western lifestyle. Ten patients with bilateral total knee arthroplasty of 2 types were studied during weight-bearing lunge, kneeling, and stair activities using fluoroscopic imaging. There were no differences in maximum knee flexion during lunging or kneeling. Statistically significant differences in tibial rotation and condylar translation were observed during the 3 activities. Although several joint kinematic differences were observed, no important functional differences were observed in clinically excellent, high performing subjects with bilateral total knee arthroplasty of 2 types.

  8. The effect of orthotic devices on knee adduction moment, pain and function in medial compartment knee osteoarthritis: a literature review.

    PubMed

    Baghaei Roodsari, Roshanak; Esteki, Ali; Aminian, Gholamreza; Ebrahimi, Ismaeil; Mousavi, Mohammad Ebramim; Majdoleslami, Basir; Bahramian, Fatemeh

    2016-03-15

    Background Knee braces and foot orthoses are commonly used to improve knee adduction moment, pain and function in subjects with knee osteoarthritis (OA). However, no literature review has been performed to compare the effects of foot orthoses and knee braces in this group of patients. Purpose The aim of this review was to evaluate the effects of foot orthoses and knee braces on knee adduction moment, pain and function in individuals with knee OA. Study design Literature review. Method The search strategy was based on the Population Intervention Comparison Outcome method. A search was performed in PubMed, Science Direct, Google Scholar and ISI web of knowledge databases using the PRISMA method and based on selected keywords. Thirty-one related articles were selected for final evaluation. Results The results of the analysis of these studies demonstrated that orthotic devices reduce knee adduction moment and also improve pain and function in individuals with knee OA. Conclusion Foot orthoses may be more effective in improving pain and function in subjects with knee OA. Both knee braces and foot orthoses reduce the knee adduction moment in knee OA and consequently patients typically do not need to use knee braces for a long period of time. Also, foot orthoses and knee braces may be more effective for medial compartment knee OA patients due to the fact that this treatment helps improve pain and function. Implications for Rehabilitation Knee braces and foot orthoses are commonly used for improving knee adduction moment, pain and function in subjects with knee osteoarthritis (OA). Orthotic devices can reduce knee adduction moment, pain and improve function in knee OA. The combined use of a knee braces and foot orthoses can provide more improvement in knee adduction moment, reduced pain and increased function.

  9. Discrete Element Modelling of Floating Debris

    NASA Astrophysics Data System (ADS)

    Mahaffey, Samantha; Liang, Qiuhua; Parkin, Geoff; Large, Andy; Rouainia, Mohamed

    2016-04-01

    Flash flooding is characterised by high velocity flows which impact vulnerable catchments with little warning time and as such, result in complex flow dynamics which are difficult to replicate through modelling. The impacts of flash flooding can be made yet more severe by the transport of both natural and anthropogenic debris, ranging from tree trunks to vehicles, wheelie bins and even storage containers, the effects of which have been clearly evident during recent UK flooding. This cargo of debris can have wide reaching effects and result in actual flood impacts which diverge from those predicted. A build-up of debris may lead to partial channel blockage and potential flow rerouting through urban centres. Build-up at bridges and river structures also leads to increased hydraulic loading which may result in damage and possible structural failure. Predicting the impacts of debris transport; however, is difficult as conventional hydrodynamic modelling schemes do not intrinsically include floating debris within their calculations. Subsequently a new tool has been developed using an emerging approach, which incorporates debris transport through the coupling of two existing modelling techniques. A 1D hydrodynamic modelling scheme has here been coupled with a 2D discrete element scheme to form a new modelling tool which predicts the motion and flow-interaction of floating debris. Hydraulic forces arising from flow around the object are applied to instigate its motion. Likewise, an equivalent opposing force is applied to fluid cells, enabling backwater effects to be simulated. Shock capturing capabilities make the tool applicable to predicting the complex flow dynamics associated with flash flooding. The modelling scheme has been applied to experimental case studies where cylindrical wooden dowels are transported by a dam-break wave. These case studies enable validation of the tool's shock capturing capabilities and the coupling technique applied between the two numerical

  10. Arthroscopic knee debridement can delay total knee replacement in painful moderate haemophilic arthropathy of the knee in adult patients.

    PubMed

    Rodriguez-Merchan, E Carlos; Gomez-Cardero, Primitivo

    2016-09-01

    The role of arthroscopic debridement of the knee in haemophilia is controversial in the literature. The purpose of this study is to describe the results of arthroscopic knee debridement (AKD), with the aim of determining whether it is possible to delay total knee replacement (TKR) for painful moderate haemophilic arthropathy of the knee in adult patients. In a 14-year period (1998-2011), AKD was performed for moderate haemophilic arthropathy of the knee in 27 patients with haemophilia A. Their average age at operation was 28.6 years (range 26-39 years). Indications for surgery were as follows: more than 90° of knee flexion, flexion deformity less than 30°, good axial alignment of the knee, good patellar alignment, and pain above >60 points in a visual analogue scale [0 (no pain) to 100 points]. Secondary haematological prophylaxis and rehabilitation (physiotherapy) was given for at least 3 months after surgery. Follow-up was for an average of 7.5 years (range 2-14 years). We assessed the clinical outcome before surgery and at the time of latest follow-up using the Knee Society pain and function scores, the range of motion, and the radiological score of the World Federation of Haemophilia. Knee Society pain scores improved from 39 preoperatively to 66 postoperatively, and function scores improved from 36 to 52. Range of motion improved on an average from -15° of extension and 90° of flexion before surgery, to -5° of extension and 110° of flexion at the last follow-up. A radiological deterioration of 2.8 points on average was found. There were two (7.4%) postoperative complications (haemarthroses resolved by joint aspiration). One patient (3.7%) required a TKR 12.5 years later. AKD should be considered in painful moderate haemophilic arthropathy of the knee in adult patients to delay TKR.

  11. KNEE-JOINT LOADING IN KNEE OSTEOARTHRITIS: INFLUENCE OF ABDOMINAL AND THIGH FAT

    PubMed Central

    Messier, Stephen P.; Beavers, Daniel P.; Loeser, Richard F.; Carr, J. Jeffery; Khajanchi, Shubham; Legault, Claudine; Nicklas, Barbara J.; Hunter, David J.; DeVita, Paul

    2014-01-01

    Purpose Using three separate models that included total body mass, total lean and total fat mass, and abdominal and thigh fat as independent measures, we determined their association with knee-joint loads in older overweight and obese adults with knee osteoarthritis (OA). Methods Fat depots were quantified using computed tomography and total lean and fat mass determined with dual energy x-ray absorptiometry in 176 adults (age = 66.3 yr., BMI = 33.5 kg·m−2) with radiographic knee OA. Knee moments and joint bone-on-bone forces were calculated using gait analysis and musculoskeletal modeling. Results Higher total body mass was significantly associated (p ≤ 0.0001) with greater knee compressive and shear forces, compressive and shear impulses (p < 0.0001), patellofemoral forces (p< 0.006), and knee extensor moments (p = 0.003). Regression analysis with total lean and total fat mass as independent variables revealed significant positive associations of total fat mass with knee compressive (p = 0.0001), shear (p < 0.001), and patellofemoral forces (p = 0.01) and knee extension moment (p = 0.008). Gastrocnemius and quadriceps forces were positively associated with total fat mass. Total lean mass was associated with knee compressive force (p = 0.002). A regression model that included total thigh and total abdominal fat found both were significantly associated with knee compressive and shear forces (p ≤ 0.04). Thigh fat was associated with the knee abduction (p = 0.03) and knee extension moment (p = 0.02). Conclusions Thigh fat, consisting predominately of subcutaneous fat, had similar significant associations with knee joint forces as abdominal fat despite its much smaller volume and could be an important therapeutic target for people with knee OA. PMID:25133996

  12. [Ossifying bursitis praepatellaris of the knee joint].

    PubMed

    Erler, M

    2009-01-01

    A 53-year-old patient was admitted to our hospital with a tumour at the site of the left knee joint praepatellar. The diagnostic imaging, operative findings and histology showed a chronic ossifying bursitis praepatellaris of the knee joint. Aetiology and pathogenesis of the ossifying bursitis are discussed.

  13. Jumper's Knee (Patellar Tendonitis) (For Parents)

    MedlinePlus

    ... regularly play sports that involve a lot of repetitive jumping — like track and field (particularly high-jumping), basketball, volleyball, gymnastics, running, and soccer — can put a lot of strain on their knees. Jumper's knee can seem like a minor injury that isn't really that serious. Because of ...

  14. Knee Braces to Prevent Injuries in Football.

    ERIC Educational Resources Information Center

    Physician and Sportsmedicine, 1986

    1986-01-01

    Five physicians discuss the use of knee braces to prevent injuries in football players. Questions are raised regarding the strength and design of the braces, whether they prestress the knee in some cases, and whether they actually reduce injuries. More clinical and biomechanical research is called for. (MT)

  15. Differences in Anatomy and Kinematics in Asian and Caucasian TKA Patients: Influence on Implant Positioning and Subsequent Loading Conditions in Mobile Bearing Knees

    PubMed Central

    Kim, Tae Kyun; Miehlke, Rolf K.; Grupp, Thomas M.

    2014-01-01

    The objective of our study was to determine the mechanical stress conditions under tibiofemoral loading with an overlay of knee kinematics in deep flexion on two different mobile bearing designs in comparison to in vivo failure modes. This study investigates the seldom but severe complication of fatigue failure of polyethylene components at mobile bearing total knee arthroplasty designs. Assuming a combination of a floor-based lifestyle and tibial malrotation as a possible reason for a higher failure rate in Asian countries we developed a simplified finite element model considering a tibiofemoral roll-back angle of 22° and the range of rotational motion of a clinically established floating platform design (e.motion FP) at a knee flexion angle of 120° in order to compare our results to failure modes found in retrieved implants. Compared to the failure mode observed in the clinical retrievals the locations of the occurring stress maxima as well as the tensile stress distribution show analogies. From our observations, we conclude that the newly introduced finite element model with an overlay of deep knee flexion (lateral roll-back) and considerable internally rotated tibia implant positioning is an appropriate analysis for knee design optimizations and a suitable method to predict clinical failure modes. PMID:25538943

  16. Epidemiology: Then and Now.

    PubMed

    Kuller, Lewis H

    2016-03-01

    Twenty-five years ago, on the 75th anniversary of the Johns Hopkins Bloomberg School of Public Health, I noted that epidemiologic research was moving away from the traditional approaches used to investigate "epidemics" and their close relationship with preventive medicine. Twenty-five years later, the role of epidemiology as an important contribution to human population research, preventive medicine, and public health is under substantial pressure because of the emphasis on "big data," phenomenology, and personalized medical therapies. Epidemiology is the study of epidemics. The primary role of epidemiology is to identify the epidemics and parameters of interest of host, agent, and environment and to generate and test hypotheses in search of causal pathways. Almost all diseases have a specific distribution in relation to time, place, and person and specific "causes" with high effect sizes. Epidemiology then uses such information to develop interventions and test (through clinical trials and natural experiments) their efficacy and effectiveness. Epidemiology is dependent on new technologies to evaluate improved measurements of host (genomics), epigenetics, identification of agents (metabolomics, proteomics), new technology to evaluate both physical and social environment, and modern methods of data collection. Epidemiology does poorly in studying anything other than epidemics and collections of numerators and denominators without specific hypotheses even with improved statistical methodologies.

  17. The acute swollen knee: diagnosis and management.

    PubMed

    Gupte, Chinmay; St Mart, Jean-Pierre

    2013-07-01

    The acutely swollen knee is a common presentation of knee pathology in both primary care and the emergency department. The key to diagnosis and management is a thorough history and examination to determine the primary pathology, which includes inflammation, infection or a structural abnormality in the knee. The location of pain and tenderness can aid to localization of structural pathology even before radiological tests are requested, and indeed inform the investigations that should be carried out. Aspiration of an acutely swollen knee can aid diagnosis and help relieve pain. The management of the swollen knee depends on underlying pathology and can range from anti-inflammatory medication for inflammation to operative intervention for a structural abnormality.

  18. Effect of implant design on knee flexion.

    PubMed

    Dennis, Douglas A; Heekin, R David; Clark, Charles R; Murphy, Jeffrey A; O'Dell, Tammy L; Dwyer, Kimberly A

    2013-03-01

    From March 2006 to August 2008, 93 subjects (186 knees) underwent simultaneous bilateral total knee arthroplasty performed by eight surgeons at North American centers. This randomized study was conducted to determine whether non-weight-bearing passive flexion was superior for knees receiving a posterior stabilized high flexion device compared to a posterior stabilized standard device in the contra-lateral knee. Weight-bearing single leg active flexion was one secondary endpoint. Follow-up compliance was 92.5%. Results show small, but significant superiority in the motion metrics for the high flexion device compared to the standard device 12 months after surgery, especially for a subgroup of patients with pre-operative flexion less than 120° in both knees. Thus, the ideal candidate for the high flexion device may be one with lesser pre-operative flexion.

  19. The acute swollen knee: diagnosis and management

    PubMed Central

    Gupte, Chinmay; St Mart, Jean-Pierre

    2013-01-01

    The acutely swollen knee is a common presentation of knee pathology in both primary care and the emergency department. The key to diagnosis and management is a thorough history and examination to determine the primary pathology, which includes inflammation, infection or a structural abnormality in the knee. The location of pain and tenderness can aid to localization of structural pathology even before radiological tests are requested, and indeed inform the investigations that should be carried out. Aspiration of an acutely swollen knee can aid diagnosis and help relieve pain. The management of the swollen knee depends on underlying pathology and can range from anti-inflammatory medication for inflammation to operative intervention for a structural abnormality. PMID:23821708

  20. Clustering of floating particles in stratified turbulence

    NASA Astrophysics Data System (ADS)

    Boffetta, Guido; de Lillo, Filippo; Musacchio, Stefano; Sozza, Alessandro

    2016-11-01

    We study the dynamics of small floating particles transported by stratified turbulence in presence of a mean linear density profile as a simple model for the confinement and the accumulation of plankton in the ocean. By means of extensive direct numerical simulations we investigate the statistical distribution of floaters as a function of the two dimensionless parameters of the problem. We find that vertical confinement of particles is mainly ruled by the degree of stratification, with a weak dependency on the particle properties. Conversely, small scale fractal clustering, typical of non-neutral particles in turbulence, depends on the particle relaxation time and is only weakly dependent on the flow stratification. The implications of our findings for the formation of thin phytoplankton layers are discussed.

  1. Nuclear Security for Floating Nuclear Power Plants

    SciTech Connect

    Skiba, James M.; Scherer, Carolynn P.

    2015-10-13

    Recently there has been a lot of interest in small modular reactors. A specific type of these small modular reactors (SMR,) are marine based power plants called floating nuclear power plants (FNPP). These FNPPs are typically built by countries with extensive knowledge of nuclear energy, such as Russia, France, China and the US. These FNPPs are built in one country and then sent to countries in need of power and/or seawater desalination. Fifteen countries have expressed interest in acquiring such power stations. Some designs for such power stations are briefly summarized. Several different avenues for cooperation in FNPP technology are proposed, including IAEA nuclear security (i.e. safeguards), multilateral or bilateral agreements, and working with Russian design that incorporates nuclear safeguards for IAEA inspections in non-nuclear weapons states

  2. Bipolar dislocation of the forearm (floating forearm).

    PubMed

    Aşkar, Hüseyin; Ertürk, Cemil; Altay, Mehmet Akif; Akif Altay, Mehmet; Bilge, Ali

    2014-01-01

    Bipolar dislocation of the forearm (floating forearm) is an unusual injury and is therefore often overlooked. We report a 28-year-old male patient who presented at another center with a history of a fall while climbing a tree. The patient's left elbow was treated with closed reduction and immobilization with a long-arm cast brace due to elbow dislocation. However, the patient was admitted with pain and swelling of the wrist to our emergency department the following day. Physical and radiological examination revealed dorsal trans-scaphoid perilunate dislocation. A dorsal incision was performed for open reduction and internal fixation to provide wide surgical exposure. Concomitant occurrence of elbow dislocation and fracture-dislocation of the perilunate is infrequent. Therefore, physicians should be aware of possible additional injuries and current recommended treatment methods.

  3. Active floating micro electrode arrays (AFMA).

    PubMed

    Kim, T; Troyk, P R; Bak, M

    2006-01-01

    Neuroscientists have widely used metal microelectrodes inserted into the cortex to record neural signals from, and provide electrical stimulation to, neural tissue for many years. Recently, the demand for implanting electrode arrays within the cortex, for both stimulation and recording, has rapidly increased. We are developing Active-floating-micro-electrode-arrays (AFMA) that are intended for use as a multielectrode cortical interface while minimizing the number of wires leading from the array to extra-dural circuitry or connectors. When combined with a wireless module, these new microelectrode arrays should allow for simulation and recording within free-roaming animals. This paper mainly discusses the design, fabrication, and packing of the first generation AFMA. Our long-term vision is a wireless-transmission electrode system, for stimulation and recording in free-roaming animals, which uses a family of modular active implantable electrode arrays.

  4. Fresh look at floating shock fitting

    NASA Technical Reports Server (NTRS)

    Hartwich, PETER-M.

    1990-01-01

    A fast implicit upwind procedure for the two-dimensional Euler equations is described that allows accurate computations of shocked flows on nonadapted meshes. Away from shocks, the second-order accurate upwinding is based on the split-coefficient-matrix (SCM) method. In the presence of shocks, the difference stencils are modified using a floating shock fitting technique. Rapid convergence to steady-state solutions is attained with a diagonalized approximate factorization (AF) algorithm. Results are presented for Riemann's problem, for a regular shock reflection at an inviscid wall, for supersonic flow past a cylinder, and for a transonic airfoil. All computed shocks are ideally sharp and in excellent agreement with other numerical results or 'exact' solutions. Most importantly, this has been accomplished on unusually crude meshes without any attempt to align grid lines with shock fronts or to cluster grid lines around shocks.

  5. Potential of water surface-floating microalgae for biodiesel production: Floating-biomass and lipid productivities.

    PubMed

    Muto, Masaki; Nojima, Daisuke; Yue, Liang; Kanehara, Hideyuki; Naruse, Hideaki; Ujiro, Asuka; Yoshino, Tomoko; Matsunaga, Tadashi; Tanaka, Tsuyoshi

    2017-03-01

    Microalgae have been accepted as a promising feedstock for biodiesel production owing to their capability of converting solar energy into lipids through photosynthesis. However, the high capital and operating costs, and high energy consumption, are hampering commercialization of microalgal biodiesel. In this study, the surface-floating microalga, strain AVFF007 (tentatively identified as Botryosphaerella sudetica), which naturally forms a biofilm on surfaces, was characterized for use in biodiesel production. The biofilm could be conveniently harvested from the surface of the water by adsorbing onto a polyethylene film. The lipid productivity of strain AVFF007 was 46.3 mg/L/day, allowing direct comparison to lipid productivities of other microalgal species. The moisture content of the surface-floating biomass was 86.0 ± 1.2%, which was much lower than that of the biomass harvested using centrifugation. These results reveal the potential of this surface-floating microalgal species as a biodiesel producer, employing a novel biomass harvesting and dewatering strategy.

  6. Gait Analysis of Conventional Total Knee Arthroplasty and Bicruciate Stabilized Total Knee Arthroplasty Using a Triaxial Accelerometer

    PubMed Central

    Saito, Hidetomo; Aizawa, Toshiaki; Miyakoshi, Naohisa; Shimada, Yoichi

    2016-01-01

    One component of conventional total knee arthroplasty is removal of the anterior cruciate ligament, and the knee after total knee arthroplasty has been said to be a knee with anterior cruciate ligament dysfunction. Bicruciate stabilized total knee arthroplasty is believed to reproduce anterior cruciate ligament function in the implant and provide anterior stability. Conventional total knee arthroplasty was performed on the right knee and bicruciate stabilized total knee arthroplasty was performed on the left knee in the same patient, and a triaxial accelerometer was fitted to both knees after surgery. Gait analysis was then performed and is reported here. The subject was a 78-year-old woman who underwent conventional total knee arthroplasty on her right knee and bicruciate stabilized total knee arthroplasty on her left knee. On the femoral side with bicruciate stabilized total knee arthroplasty, compared to conventional total knee arthroplasty, there was little acceleration in the x-axis direction (anteroposterior direction) in the early swing phase. Bicruciate stabilized total knee arthroplasty may be able to replace anterior cruciate ligament function due to the structure of the implant and proper anteroposterior positioning. PMID:27648328

  7. [Jumper's knee--a review].

    PubMed

    Tibesku, C O; Pässler, H H

    2005-06-01

    Jumper's knee has been defined as painful chronic overuse injury of the extensor mechanism of the knee joint. The disease has a high incidence in jumping sports and depends on training frequency and level of performance. Its natural course is protracted, repetitive, and often bilaterally occurring. Its etiology is a chronic overload of the knee extensor mechanism which is triggered by jumping sports (volleyball, basketball etc.) as well as different intrinsic (ligamentous laxity, Q-angle, patella height, tenderness, pattern of force development) and extrinsic dispositions (frequency of training, level of performance, hardness of underground). The place of pathology most often is the osteo-tendinous transition zone of the proximal patellar tendon. Histologic evaluation of the tendon showed that the disease is rather degenerative than inflammatory. The diagnosis is primarily based on the typical sports history, physical examination, and ultrasound. MRI is helpful in operation planning. Plain radiography, CT, and bone scans are used to rule out differential diagnoses. Therapy should be chosen according to the stage of the disease and usually starts with a non-surgical approach. This includes rest from sports activities, immobilisation, non-steroid antiphlogistics, para-tendinous cortisone injections, massage, electric therapy, ultrasound and extracorporal shock waves. Afterwards an increase of activities is begun (moderate training, adequate warm-up, ice cooling after activity, muscle stretching, eccentric strengthening of the quadriceps). Patella straps and soft insoles are used as prevention. Up to 42 % of patients need surgical therapy after failure of long-lasting non-surgical measures, carried out either open or arthroscopically. Surgical principles include excision of the para-tendon, excision of the degenerative tissue, resection of the lower patella pole, and longitudinal incisions into the tendon. Most patients are pain-free after surgery but return to sports

  8. WindWaveFloat (WWF): Final Scientific Report

    SciTech Connect

    Alla Weinstein; Roddier, Dominique; Banister, Kevin

    2012-03-30

    Principle Power Inc. and National Renewable Energy Lab (NREL) have completed a contract to assess the technical and economic feasibility of integrating wave energy converters into the WindFloat, resulting in a new concept called the WindWaveFloat (WWF). The concentration of several devices on one platform could offer a potential for both economic and operational advantages. Wind and wave energy converters can share the electrical cable and power transfer equipment to transport the electricity to shore. Access to multiple generation devices could be simplified, resulting in cost saving at the operational level. Overall capital costs may also be reduced, provided that the design of the foundation can be adapted to multiple devices with minimum modifications. Finally, the WindWaveFloat confers the ability to increase energy production from individual floating support structures, potentially leading to a reduction in levelized energy costs, an increase in the overall capacity factor, and greater stability of the electrical power delivered to the grid. The research conducted under this grant investigated the integration of several wave energy device types into the WindFloat platform. Several of the resulting system designs demonstrated technical feasibility, but the size and design constraints of the wave energy converters (technical and economic) make the WindWaveFloat concept economically unfeasible at this time. Not enough additional generation could be produced to make the additional expense associated with wave energy conversion integration into the WindFloat worthwhile.

  9. Criticality in epidemiology

    NASA Astrophysics Data System (ADS)

    Stollenwerk, Nico; Jansen, Vincent A. A.

    For a long time criticality has been considered in epidemiological models. We review the body of theory developed over the last twenty five years for the simplest models. It is at first glance difficult to imagine that an epidemiological system operates at a very fine tuned critical state as opposed to any other parameter region. However, the advent of self-organized criticality has given hints in how to interpret large fluctuations observed in many natural systems including epidemiological systems. We show some scenarios where criticality has been observed (e.g., measles under vaccination) and where evolution towards a critical state can explain fluctuations (e.g., meningococcal disease.)

  10. Radionuclide therapy for arthritic knees

    SciTech Connect

    Doepel, L.K.

    1985-02-08

    A new radionuclide therapeutic approach for rheumatoid arthritis of the knee is described. This therapy combines a short-lived radionuclide with a carrier whose physical and chemical characteristics aid retention of the radioactive particles within the joint. Joining a radionuclide to a particulate carrier had not been explored previously as a potential method for inhibiting radiation leakage. The treatment couples the rare earth element dysprosium 165 to ferric hydroxide in macroaggregate form (size range: 3 to 10 ..mu..m). After the relatively inert iron complex penetrates the synovium, it causes cell death. Macrophages and phagocytes clear away the cellular debris, essentially eliminating the synovium.

  11. Automatic locking knee brace joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce (Inventor)

    1995-01-01

    This invention is an apparatus for controlling the pivotal movement of a knee brace comprising a tang-and-clevis joint that has been uniquely modified. Both the tang and the clevis have a set of teeth that, when engaged, can lock the tang and the clevis together. In addition, the tang is biased away from the clevis. Consequently, when there is no axial force (i.e., body weight) on the tang, the tang is free to pivot within the clevis. However, when an axial force is exerted on the tang, the tang is pushed into the clevis, both sets of teeth engage, and the tang and the clevis lock together.

  12. Molecular Biomarkers of Knee Pathology.

    PubMed

    Cuellar, Vanessa; Strauss, Eric

    2017-01-01

    The identification of biomarkers has become increasingly important in our fundamental understanding of the molecular basis for disease and subsequently in the advancement of modern medicine. Biomarkers have been identified in a plethora of normal and pathologic conditions and are most often found in blood, tissue, or synovial fluid. Orthopaedic research has more recently focused on biomarkers of cartilage and joint diseases, with an emphasis on understanding the molecular underpinnings of their pathophysiology. This article focuses on the biomarkers identified to date in several select knee pathologies and how further research can contribute to new diagnostic tools and targeted therapeutics.

  13. MRI EVALUATION OF KNEE CARTILAGE

    PubMed Central

    Rodrigues, Marcelo Bordalo; Camanho, Gilberto Luís

    2015-01-01

    Through the ability of magnetic resonance imaging (MRI) to characterize soft tissue noninvasively, it has become an excellent method for evaluating cartilage. The development of new and faster methods allowed increased resolution and contrast in evaluating chondral structure, with greater diagnostic accuracy. In addition, physiological techniques for cartilage assessment that can detect early changes before the appearance of cracks and erosion have been developed. In this updating article, the various techniques for chondral assessment using knee MRI will be discussed and demonstrated. PMID:27022562

  14. Float level switch for a nuclear power plant containment vessel

    DOEpatents

    Powell, James G.

    1993-01-01

    This invention is a float level switch used to sense rise or drop in water level in a containment vessel of a nuclear power plant during a loss of coolant accident. The essential components of the device are a guide tube, a reed switch inside the guide tube, a float containing a magnetic portion that activates a reed switch, and metal-sheathed, ceramic-insulated conductors connecting the reed switch to a monitoring system outside the containment vessel. Special materials and special sealing techniques prevent failure of components and allow the float level switch to be connected to a monitoring system outside the containment vessel.

  15. Defining the IEEE-854 floating-point standard in PVS

    NASA Technical Reports Server (NTRS)

    Miner, Paul S.

    1995-01-01

    A significant portion of the ANSI/IEEE-854 Standard for Radix-Independent Floating-Point Arithmetic is defined in PVS (Prototype Verification System). Since IEEE-854 is a generalization of the ANSI/IEEE-754 Standard for Binary Floating-Point Arithmetic, the definition of IEEE-854 in PVS also formally defines much of IEEE-754. This collection of PVS theories provides a basis for machine checked verification of floating-point systems. This formal definition illustrates that formal specification techniques are sufficiently advanced that is is reasonable to consider their use in the development of future standards.

  16. A floating gate MOSFET dosimeter requiring no external bias supply

    SciTech Connect

    Tarr, N.G.; Mackay, G.F.; Thomson, I.; Shortt, K.

    1998-06-01

    MOSFET dosimeters incorporating an electrically floating polysilicon gate have been fabricated in a commercial CMOS technology. Charge is placed on the floating gate by tunneling from a small overlapping injector gate. Subsequent irradiation partially discharges the floating gate, producing a change in threshold voltage which can be used to infer the absorbed dose. No external power source is required during this sensing period. Sensitivities up to 70 mVGy{sup {minus}1} (0.7 mV/rad) have been obtained for temperature-compensated matched-pair dosimeters under {sup 60}Co gamma irradiation.

  17. Radiation Issues and Applications of Floating Gate Memories

    NASA Technical Reports Server (NTRS)

    Scheick, L. Z.; Nguyen, D. N.

    2000-01-01

    The radiation effects that affect various systems that comprise floating gate memories are presented. The wear-out degradation results of unirradiated flash memories are compared to irradiated flash memories. The procedure analyzes the failure to write and erase caused by wear-out and degradation of internal charge pump circuits. A method is described for characterizing the radiation effects of the floating gate itself. The rate dependence, stopping power dependence, SEU susceptibility and applications of floating gate in radiation environment are presented. The ramifications for dosimetry and cell failure are discussed as well as for the long term use aspects of non-volatile memories.

  18. Float level switch for a nuclear power plant containment vessel

    DOEpatents

    Powell, J.G.

    1993-11-16

    This invention is a float level switch used to sense rise or drop in water level in a containment vessel of a nuclear power plant during a loss of coolant accident. The essential components of the device are a guide tube, a reed switch inside the guide tube, a float containing a magnetic portion that activates a reed switch, and metal-sheathed, ceramic-insulated conductors connecting the reed switch to a monitoring system outside the containment vessel. Special materials and special sealing techniques prevent failure of components and allow the float level switch to be connected to a monitoring system outside the containment vessel. 1 figures.

  19. Floating potential measurements in plasmas: From dust to spacecraft

    NASA Astrophysics Data System (ADS)

    Beadles, R.; Wang, X.; Horányi, M.

    2017-02-01

    We present measurements of the floating potential of spherical probes, used as a model of a dust particle or a spacecraft, immersed in plasmas with a wide range of Debye lengths. Our experimental results verified the theoretical prediction that the probe floating potential is a function of the Debye length. It is shown that, in an argon plasma with the ion to electron temperature ratio ˜0.01, the magnitude of the floating potential is approximately doubled when the Debye length is changed from larger to smaller than the radius of the probe.

  20. Strongly Emitting Surfaces Unable to Float below Plasma Potential

    DOE PAGES

    Campanell, M. D.; Umansky, M. V.

    2016-02-25

    One important unresolved question in plasma physics concerns the effect of strong electron emission on plasma-surface interactions. Previous papers reported solutions with negative and positive floating potentials relative to the plasma edge. For these two models a very different predictions for particle and energy balance is given. Here we show that the positive potential state is the only possible equilibrium in general. Even if a negative floating potential existed at t=0, the ionization collisions near the surface will force a transition to the positive floating potential state. Moreover, this transition is demonstrated with a new simulation code.

  1. Epidemiology of Injuries and Prevention Strategies in Competitive Swimmers

    PubMed Central

    Wanivenhaus, Florian; Fox, Alice J. S.; Chaudhury, Salma; Rodeo, Scott A.

    2012-01-01

    Context: Competitive swimmers are predisposed to musculoskeletal injuries of the upper limb, knee, and spine. This review discusses the epidemiology of these injuries, in addition to prevention strategies that may assist the physician in formulating rehabilitation programs for the swimmer following an injury. Evidence Acquisition: A literature search was performed by a review of Google Scholar, OVID, and PubMed articles published from 1972 to 2011. Results: This study highlights the epidemiology of injuries common to competitive swimmers and provides prevention strategies for the sports health professional. Conclusions: An understanding of swimming biomechanics and typical injuries in swimming aids in early recognition of injury, initiation of treatment, and design of optimal prevention and rehabilitation strategies. PMID:23016094

  2. 46 CFR 160.027-3 - Additional requirements for life floats.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Additional requirements for life floats. 160.027-3..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Floats for Merchant Vessels § 160.027-3 Additional requirements for life floats. (a) Each life float must have a platform...

  3. Knee injuries account for the sports-related increased risk of knee osteoarthritis.

    PubMed

    Thelin, N; Holmberg, S; Thelin, A

    2006-10-01

    Increased risk of osteoarthritis has been found among athletes active in different kinds of sports. Knee injury is an established risk factor for knee osteoarthritis. In this population-based case-control study we investigated the risk of knee osteoarthritis with respect to sports activity and previous knee injuries. A total of 825 cases with x-ray-verified femorotibial osteoarthritis were identified at six hospitals in southern Sweden. The cases were matched (age, sex and residential area) with 825 controls from the general population. Mailed questionnaire data on sports activity for more than 1 year after the age of 16, knee injuries and confounding variables (weight, height, heredity, smoking and occupation) were collected and analyzed using logistic regression models. The response frequency was 89%. Among men knee osteoarthritis was related to soccer (odds ratio (OR) 1.6, 95% confidence interval (CI) 1.1-2.2), ice hockey (OR 1.9, 95% CI 1.2-3.0) and tennis (OR 2.0, 95% CI 1.1-3.8) but not to track and field sports, cross-country skiing, and orienteering. After adjustment for confounding variables soccer and ice hockey remained significantly related to knee osteoarthritis, but after adjustment for knee injuries no significant relation remained. The sports-related increased risk for knee osteoarthritis was explained by knee injuries.

  4. Real-Time Tracking of Knee Adduction Moment in Patients with Knee Osteoarthritis

    PubMed Central

    Kang, Sang Hoon; Lee, Song Joo; Zhang, Li-Qun

    2014-01-01

    Background The external knee adduction moment (EKAM) is closely associated with the presence, progression, and severity of knee osteoarthritis (OA). However, there is a lack of convenient and practical method to estimate and track in real-time the EKAM of patients with knee OA for clinical evaluation and gait training, especially outside of gait laboratories. New Method A real-time EKAM estimation method was developed and applied to track and investigate the EKAM and other knee moments during stepping on an elliptical trainer in both healthy subjects and a patient with knee OA. Results Substantial changes were observed in the EKAM and other knee moments during stepping in the patient with knee OA. Comparison with Existing Method(s) This is the first study to develop and test feasibility of real-time tracking method of the EKAM on patients with knee OA using 3-D inverse dynamics. Conclusions The study provides us an accurate and practical method to evaluate in real-time the critical EKAM associated with knee OA, which is expected to help us to diagnose and evaluate patients with knee OA and provide the patients with real-time EKAM feedback rehabilitation training. PMID:24361759

  5. Anterior knee pain and cold knees: a possible association in women.

    PubMed

    Selfe, James; Sutton, Chris; Hardaker, Natalie J; Greenhalgh, Sue; Karki, Anne; Dey, Paola

    2010-10-01

    Abnormal reactions to environmental cold have been observed in some patients with Anterior Knee Pain (AKP). The aims of this study were to investigate whether palpation of the knee could classify patients into those with and those without cold knees; whether this classification could be objectively validated using thermal imaging; whether the cold and not cold knee groups varied in response to a cold stress test and in patient-reported measures. Fifty eight patients were recruited; palpation classified them into cold and not cold groups. Twenty-one (36%) patients were classified as having a cold knee by palpation: fourteen (36%) females and seven males (37%). Preliminary analysis suggested gender might be an effect modifier and the number of men was small, therefore the analysis focussed on females. Women with cold knees had a significantly smaller patellar skin fold, lower levels of activity and worse scores on the MFIQ, there also appeared to be an association with a traumatic onset. Women with cold knees were more likely to report cold weather affected their knees and they preferred a hot water bottle compared to an ice-pack on their knee; there was also a trend towards having to wear extra tights/long johns in the winter. This study has helped to define a clinical profile for a group of females with AKP and cold knees. This group appears to demonstrate a mild form of Reflex Sympathetic Dystrophy.

  6. Six degree-of-freedom knee joint kinematics in obese individuals with knee pain during gait

    PubMed Central

    Li, Jing-Sheng; Tsai, Tsung-Yuan; Felson, David T.; Li, Guoan; Lewis, Cara L.

    2017-01-01

    Knee joint pain is a common symptom in obese individuals and walking is often prescribed as part of management programs. Past studies in obese individuals have focused on standing alignment and kinematics in the sagittal and coronal planes. Investigation of 6 degree-of-freedom (6DOF) knee joint kinematics during standing and gait is important to thoroughly understand knee function in obese individuals with knee pain. This study aimed to investigate the 6DOF knee joint kinematics in standing and during gait in obese patients using a validated fluoroscopic imaging system. Ten individuals with obesity and knee pain were recruited. While standing, the knee was in 7.4±6.3°of hyperextension, 2.8±3.3° of abduction and 5.6±7.3° of external rotation. The femoral center was located 0.7±3.1mm anterior and 5.1±1.5mm medial to the tibial center. During treadmill gait, the sagittal plane motion, i.e., flexion/extension and anterior-posterior translation, showed a clear pattern. Specifically, obese individuals with knee pain maintained the knee in more flexion and more anterior tibial translation during most of the stance phase of the gait cycle and had a reduced total range of knee flexion when compared to a healthy non-obese group. In conclusion, obese individuals with knee pain used hyperextension knee posture while standing, but maintained the knee in more flexion during gait with reduced overall range of motion in the 6DOF analysis. PMID:28339477

  7. Three-dimensional dynamic analysis of knee joint during gait in medial knee osteoarthritis using loading axis of knee.

    PubMed

    Nishino, Katsutoshi; Omori, Go; Koga, Yoshio; Kobayashi, Koichi; Sakamoto, Makoto; Tanabe, Yuji; Tanaka, Masaei; Arakawa, Masaaki

    2015-07-01

    We recently developed a new method for three-dimensional evaluation of mechanical factors affecting knee joint in order to help identify factors that contribute to the progression of knee osteoarthritis (KOA). This study aimed to verify the clinical validity of our method by evaluating knee joint dynamics during gait. Subjects were 41 individuals (14 normal knees; 8 mild KOAs; 19 severe KOAs). The positions of skin markers attached to the body were captured during gait, and bi-planar X-ray images of the lower extremities were obtained in standing position. The positional relationship between the markers and femorotibial bones was determined from the X-ray images. Combining this relationship with gait capture allowed for the estimation of relative movement between femorotibial bones. We also calculated the point of intersection of loading axis of knee on the tibial proximal surface (LAK point) to analyze knee joint dynamics. Knee flexion range in subjects with severe KOA during gait was significantly smaller than that in those with normal knees (p=0.011), and knee adduction in those with severe KOA was significantly larger than in those with mild KOA (p<0.000). LAK point was locally loaded on the medial compartment of the tibial surface as KOA progressed, with LAK point of subjects with severe KOA rapidly shifting medially during loading response. Local loading and medial shear force were applied to the tibial surface during stance phase as medial KOA progressed. Our findings suggest that our method is useful for the quantitative evaluation of mechanical factors that affect KOA progression.

  8. Epidemiology of Lice

    ERIC Educational Resources Information Center

    Juranek, Dennis D.

    1977-01-01

    Research into the epidemiology of lice indicates that infestation is uncommon in blacks, more common in females than males, significantly higher in low income groups, and transmission is by way of articles of clothing. (JD)

  9. Epidemiology & Genomics Research Program

    Cancer.gov

    The Epidemiology and Genomics Research Program, in the National Cancer Institute's Division of Cancer Control and Population Sciences, funds research in human populations to understand the determinants of cancer occurrence and outcomes.

  10. EPIDEMIOLOGY AND EXPOSURE ASSESSMENT

    EPA Science Inventory

    Research collaborations between the National Health and Environmental Effects Research Laboratory (NHEERL) and the National Exposure Research Laboratory (NERL) centered on the development and application of exposure analysis tools in environmental epidemiology include the El Paso...

  11. Cancer Epidemiology Cohorts

    Cancer.gov

    Cohort studies are fundamental for epidemiological research by helping researchers better understand the etiology of cancer and provide insights into the key determinants of this disease and its outcomes.

  12. Can a finite set of knee extension in supine position be used for a knee functional examination?

    PubMed

    Marin, F; Sangeux, M; Charleux, F; Ho Ba Tho, M-C; Dürselen, L

    2006-01-01

    The kinematic magnetic resonance imaging technique has been developed to provide a functional examination of the knee. Technical limitations require this examination to be performed in supine position, and the knee motion is represented by an assembly of static positions at different knee angles. However, the main knee function is to support the body weight and perform continuous motion, e.g. parallel squat. Our study quantified the knee kinematics of 20 healthy subjects in different motion conditions (finite and continuous) and in different mechanical conditions (continuous unloaded and continuous loaded). We evaluated the angular and localisation difference of a finite helical axis of the knee motion for parallel squat, continuous knee extension in supine position and the finite set of knee extension in supine position. We found large inter-individual dispersion. The majority of subjects had equivalent knee kinematics between continuous knee extension and the finite set of knee extension in supine position, but not between continuous knee extension in supine position and the parallel squat. Therefore, results from a functional examination of a finite set of knee extensions in supine position do not represent the knee motion in a parallel squat. Our results suggest that functional examination of the knee from magnetic resonance imaging do not necessarily reflect the physiological kinematics of the knee. Further investigation should focus on a new magnetic resonance imaging acquisition protocol that allows image acquisition during weight bearing or includes a special device which reproduces the loaded condition.

  13. Intraoperative knee anthropometrics: correlation with cartilage wear.

    PubMed

    Rooney, N; Fitzpatrick, D P; Beverland, D E

    2006-08-01

    Accurate knee morphology is of value in determining the correct sizing of prosthetic implants. Intraoperative measurement of key linear dimensional variables was carried out on 196 Caucasian knees (osteoarthritic patients: 68 male and 128 female). Of the 196 knees measured, 70 had extensive cartilage degeneration. Statistical analysis was carried out on this large sample size of data. Summary statistics and correlation coefficients between variables were determined and compared between subgroups. Male knees were on average larger than female knees. Higher correlation was found between variables for males than between variables for females. Overall, the patellar dimensions were seen to correlate least well with other anatomical variables. High correlation between femoral variables supports current femoral sizing procedure, although routine patellar resection practices are called into question. Average values for the 70 knees with extensive cartilage degeneration were significantly smaller (P < 0.01) than their counterparts for the other 126 knees. For a measurement not containing cartilage, such as femoral epicondylar width, this difference cannot be accounted for by the loss of cartilage owing to wear. This suggests that, for similar height and weight, a naturally narrower femoral epicondylar width may be associated with severe osteoarthritis.

  14. Signed-digit online floating-point arithmetic for FPGAs

    NASA Astrophysics Data System (ADS)

    Tangtrakul, Atakorn; Yeung, Benjamin; Cook, Todd A.

    1996-10-01

    Many potential applications for reconfigurable computing need the dynamic range provided by floating-point arithmetic. However, doing floating-point on FPGAs is difficult because of the large amount of hardware required, particularly for multipliers. Some limited success has been obtained through digit-serial implementation of IEEE floating-point multipliers, but the IEEE representation is not easily or efficiently implemented in serial form. Therefore, we have been exploring alternate number representations. Signed-digit representations have shown some promise, since their form lends them to serial computation, which consumes much less hardware than fully parallel approaches. We show how the signed-digit representation can be used to implement floating-point arithmetic, and we present prototype implementations using Altera FPGAs.

  15. Multifractal analysis of managed and independent float exchange rates

    NASA Astrophysics Data System (ADS)

    Stošić, Darko; Stošić, Dusan; Stošić, Tatijana; Stanley, H. Eugene

    2015-06-01

    We investigate multifractal properties of daily price changes in currency rates using the multifractal detrended fluctuation analysis (MF-DFA). We analyze managed and independent floating currency rates in eight countries, and determine the changes in multifractal spectrum when transitioning between the two regimes. We find that after the transition from managed to independent float regime the changes in multifractal spectrum (position of maximum and width) indicate an increase in market efficiency. The observed changes are more pronounced for developed countries that have a well established trading market. After shuffling the series, we find that the multifractality is due to both probability density function and long term correlations for managed float regime, while for independent float regime multifractality is in most cases caused by broad probability density function.

  16. CANVAS FINISH TO REMOVE FLOAT MARKS. View is to the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CANVAS FINISH TO REMOVE FLOAT MARKS. View is to the northwest of deck finishing operations - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

  17. 16. EAST ELEVATION OF FLOAT HOUSE AND FISH WATER RELEASE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. EAST ELEVATION OF FLOAT HOUSE AND FISH WATER RELEASE OUTLET. PART OF ENERGY DISSIPATING BAFFLE PIER SYSTEM IS VISIBLE AT LEFT. - Pit 4 Diversion Dam, Pit River west of State Highway 89, Big Bend, Shasta County, CA

  18. 50. (no plate) Lens, lens pedestal, mercury float, drawing # ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. (no plate) Lens, lens pedestal, mercury float, drawing # 3101, sheet 1 of 2. Approved April 6, 1928. - Block Island Southeast Light, Spring Street & Mohegan Trail at Mohegan Bluffs, New Shoreham, Washington County, RI

  19. 51. (no plate) Lens, lens pedestal, mercury float, shade holder ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. (no plate) Lens, lens pedestal, mercury float, shade holder installation, drawing # 3101, sheet 2 of 2. Approved April 6, 1928. - Block Island Southeast Light, Spring Street & Mohegan Trail at Mohegan Bluffs, New Shoreham, Washington County, RI

  20. 26. Mechanical float gages used to monitor level of water ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. Mechanical float gages used to monitor level of water in the filtration bed reservoir. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  1. High voltage switches having one or more floating conductor layers

    SciTech Connect

    Werne, Roger W.; Sampayan, Stephen; Harris, John Richardson

    2015-11-24

    This patent document discloses high voltage switches that include one or more electrically floating conductor layers that are isolated from one another in the dielectric medium between the top and bottom switch electrodes. The presence of the one or more electrically floating conductor layers between the top and bottom switch electrodes allow the dielectric medium between the top and bottom switch electrodes to exhibit a higher breakdown voltage than the breakdown voltage when the one or more electrically floating conductor layers are not present between the top and bottom switch electrodes. This increased breakdown voltage in the presence of one or more electrically floating conductor layers in a dielectric medium enables the switch to supply a higher voltage for various high voltage circuits and electric systems.

  2. Translational and rotational knee joint stability in anterior and posterior cruciate-retaining knee arthroplasty.

    PubMed

    Lo, JiaHsuan; Müller, Otto; Dilger, Torsten; Wülker, Nikolaus; Wünschel, Markus

    2011-12-01

    This study investigated passive translational and rotational stability properties of the intact knee joint, after bicruciate-retaining bi-compartmental knee arthroplasty (BKA) and after posterior cruciate retaining total knee arthroplasty (TKA). Fourteen human cadaveric knee specimens were used in this study, and a robotic manipulator with six-axis force/torque sensor was used to test the joint laxity in anterior-posterior translation, valgus-varus, and internal-external rotation. The results show the knee joint stability after bicruciate-retaining BKA is similar to that of the native knee. On the other hand, the PCL-retaining TKA results in inferior joint stability in valgus, varus, external rotation, anterior and, surprisingly, posterior directions. Our findings suggest that, provided functional ligamentous structures, bicruciate-retaining BKA is a biomechanically attractive treatment for joint degenerative disease.

  3. Human knee joint anatomy revisited: morphometry in the light of sex-specific total knee arthroplasty.

    PubMed

    Dargel, Jens; Michael, Joern W P; Feiser, Janna; Ivo, Roland; Koebke, Juergen

    2011-04-01

    This study investigates differences in the anatomy of male and female knee joints to contribute to the current debate on sex-specific total knee implants. Morphometric data were obtained from 60 human cadaver knees, and sex differences were calculated. All data were corrected for height, and male and female specimens presenting with an identical length of the femur were analyzed as matched pairs. Male linear knee joint dimensions were significantly larger when compared with females. When corrected for differences in height, medial-lateral dimensions of male knees were significantly larger than female; however, matched paired analysis did not prove these differences to be consistent. Although implant design should focus interindividual variations in knee joint anatomy, our data do not support the concept of a female-specific implant design.

  4. Knee range of motion after total knee arthroplasty: how important is this as an outcome measure?

    PubMed

    Miner, Andrew L; Lingard, Elizabeth A; Wright, Elizabeth A; Sledge, Clement B; Katz, Jeffrey N

    2003-04-01

    We investigated the relationship of knee range of motion (ROM) and function in a prospective, observational study of primary total knee arthroplasty (TKA). Preoperative and 12-month data were collected on 684 patients, including knee ROM, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function questionnaire scores, patient satisfaction, and perceived improvement in quality of life (QOL). Only modest correlations were found between knee ROM and WOMAC function (r<0.34). At 12 months we found significantly worse WOMAC function scores for patients with <95 degrees flexion compared with patients with > or =95 degrees (mean, 61.9 vs 75.0; P<.0001). In linear regression models, WOMAC pain and function scores at 12 months were both correlates of patient satisfaction and perceived improvement in QOL (standardized beta>3.5; P<.0001), but knee flexion was not. For assessment of these outcomes, WOMAC function appears to be more important than knee flexion.

  5. In vivo knee kinematics during stair and deep flexion activities in patients with bicruciate substituting total knee arthroplasty.

    PubMed

    Kuroyanagi, Yuji; Mu, Shang; Hamai, Satoshi; Robb, William J; Banks, Scott A

    2012-01-01

    Orthopedic surgeons and their patients continue to seek better functional outcomes after total knee arthroplasty. The bicruciate substituting (BCS) total knee arthroplasty design has been introduced to achieve more natural knee mechanics. The purpose of this study was to characterize kinematics in knees with BCS arthroplasty during deep flexion and stair activities using fluoroscopy and model-image registration. In 20 patients with 25 BCS knees, we observed average implant flexion of 128° during kneeling and consistent posterior condylar translations with knee flexion. Tibial rotations were qualitatively similar to those observed in the arthritic natural knee. Knee kinematics with BCS arthroplasty were qualitatively more similar to arthritic natural knees than knees with either posterior cruciate-retaining or posterior-stabilized arthroplasty.

  6. Parametric time delay modeling for floating point units

    NASA Astrophysics Data System (ADS)

    Fahmy, Hossam A. H.; Liddicoat, Albert A.; Flynn, Michael J.

    2002-12-01

    A parametric time delay model to compare floating point unit implementations is proposed. This model is used to compare a previously proposed floating point adder using a redundant number representation with other high-performance implementations. The operand width, the fan-in of the logic gates and the radix of the redundant format are used as parameters to the model. The comparison is done over a range of operand widths, fan-in and radices to show the merits of each implementation.

  7. Crystal Growth in Liquid-Encapsulated Float Zone

    NASA Technical Reports Server (NTRS)

    Naumann, Robert J.; Frazier, Donald O.; Lehoczky, Sandor; Vlasse, Marcus; Facemire, Barbara

    1987-01-01

    Suitably chosen liquid encapsulant placed around melt zone in float-zone crystal-growth system performs four important functions enhancing purity and reducing strains and dislocations in final crystal. In new technique, grow dislocation-free crystals with precisely controlled composition even from materials not amenable to conventional float-zone crystal-growth method. Support provided by encapsulant make it practical to process materials of low surface tension.

  8. Comparative evaluation of single and bilayered lamotrigine floating tablets

    PubMed Central

    Lakshmi, PK; Sridhar, M; Shruthi, B

    2013-01-01

    Aim: The purpose of this study was to prepare lamotrigine (LM) bilayered and single layered floating tablets and to compare their release profiles. Materials and Methods: LM floating tablets were prepared by direct compression method. Drug, hydroxy propyl methyl cellulose K4M, lactose monohydrate and polyvinylpyrrolidone K30 constitute controlled release layer components and floating layer components includes polymers and sodium bicarbonate. The prepared tablets were evaluated for physicochemical parameters such as hardness, friability, weight variation, thickness, floating lag time (FLT), floating time, in vitro buoyancy study, in vitro release studies. The drug-polymer interaction was studied by fourier transform infrared and differential scanning calorimetry. Results and Discussion: The FLT of all the formulations were within the prescribed limits (<3 min). When ethyl cellulose was used as floating layer component, tablets showed good buoyancy effect but eroded within 6-8 h. Hence it was replaced with hydroxypropyl cellulose -M hydrophilic polymer, which showed good FLT and floating duration for 16 h. Formulation LFC4 was found to be optimized with dissolution profile of zero order kinetics showing fickian diffusion. A comparative study of bilayered and single layered tablets of LM showed a highest similarity factor of 83.03, difference factor of 2.74 and t-test (P < 0.05) indicates that there is no significant difference between them. Conclusion: Though bilayered tablet possess many advantages, single layered tablet would be economical, cost-effective and reproducible for large scale production in the industry. However, the results of present study demonstrated that the in vitro development of bilayered gastro retentive floating tablets with controlled drug release profile for LM is feasible. PMID:24167788

  9. Osteotomies about the knee: AAOS exhibit selection.

    PubMed

    Uquillas, Carlos; Rossy, William; Nathasingh, Christopher K; Strauss, Eric; Jazrawi, Laith; Gonzalez-Lomas, Guillem

    2014-12-17

    Varus or valgus malalignment of the lower extremity can alter the load distribution across the knee and hasten the development of focal osteoarthritis. Although knee arthroplasty remains an effective option for end-stage arthritis, it is not typically recommended in the young, active patient. In the setting of painful unicompartmental cartilage injury in a mechanically malaligned limb, alignment correction by osteotomy has been shown to slow the progression of osteoarthritis and lessen pain. In this review, we will discuss the different options, indications, and techniques for osteotomies about the knee.

  10. SYNOVIAL GIANT CELL TUMOR OF THE KNEE.

    PubMed

    Abdalla, Rene Jorge; Cohen, Moisés; Nóbrega, Jezimar; Forgas, Andrea

    2009-01-01

    Synovial giant cell tumor is a benign neoplasm, rarely reported in the form of malignant metastasis. Synovial giant cell tumor most frequently occurs on the hand, and, most uncommon, on the ankle and knee. In the present study, the authors describe a rare case of synovial giant cell tumor on the knee as well as the treatment approach. Arthroscopy has been shown, in this case, to be the optimal method for treating this kind of lesion, once it allowed a less aggressive approach, while providing good visualization of all compartments of knee joint and full tumor resection.

  11. Which osteotomy for a valgus knee?

    PubMed Central

    Cipolla, Massimo; Cerullo, Guglielmo; Franco, Vittorio; Giannì, Enrico

    2009-01-01

    A valgus knee is a disabling condition that can affect patients of all ages. Antivalgus osteotomy of the knee is the treatment of choice to correct the valgus, to eliminate pain in the young or middle age patient, and to avoid or delay a total knee replacement. A distal femoral lateral opening wedge procedure appears to be one of the choices for medium or large corrections and is particularly easy and precise if compared to the medial femoral closing wedge osteotomy. However, if the deformity is minimal, a tibial medial closing wedge osteotomy can be done with a faster healing and a short recovery time. PMID:19547972

  12. Gap balancing in total knee arthroplasty.

    PubMed

    Bottros, John; Gad, Bishoy; Krebs, Viktor; Barsoum, Wael K

    2006-06-01

    It is well known that the success of total knee arthroplasty is collectively dependent on the proper recreation of the joint line, appropriate soft tissue balancing, and respectful management of the extensor mechanism. One of the most decisive factors within the surgeon's control is the reestablishment of proper knee kinematics through both medial-lateral and flexion-extension ligamentous balancing. This can be accomplished only by a comprehensive intraoperative evaluation in full flexion, mid flexion, and full extension to minimize potential gap mismatches. Most of the discussion will focus on this aspect of soft tissue balancing, but this does not undermine the importance of the other aforementioned principles of successful knee arthroplasty.

  13. Proprioception and Knee Arthroplasty: A Literature Review.

    PubMed

    Wodowski, Andrew J; Swigler, Colin W; Liu, Hongchao; Nord, Keith M; Toy, Patrick C; Mihalko, William M

    2016-04-01

    Proprioceptive mechanoreceptors provide neural feedback for position in space and are critical for three-dimensional interaction. Proprioception is decreased with osteoarthritis of the knees, which leads to increased risk of falling. As the prevalence of osteoarthritis increases so does the need for total knee arthroplasty (TKA), and knowing the effect of TKA on proprioception is essential. This article reviews the literature regarding proprioception and its relationship to balance, aging, osteoarthritis, and the effect of TKA on proprioception. Knee arthroplasty involving retention of the cruciate ligaments is also reviewed, as well the evidence of proprioception in the posterior cruciate ligament after TKA.

  14. SYNOVIAL GIANT CELL TUMOR OF THE KNEE

    PubMed Central

    Abdalla, Rene Jorge; Cohen, Moisés; Nóbrega, Jezimar; Forgas, Andrea

    2015-01-01

    Synovial giant cell tumor is a benign neoplasm, rarely reported in the form of malignant metastasis. Synovial giant cell tumor most frequently occurs on the hand, and, most uncommon, on the ankle and knee. In the present study, the authors describe a rare case of synovial giant cell tumor on the knee as well as the treatment approach. Arthroscopy has been shown, in this case, to be the optimal method for treating this kind of lesion, once it allowed a less aggressive approach, while providing good visualization of all compartments of knee joint and full tumor resection. PMID:27004193

  15. Epidemiology of Locomotive Organ Disorders and Symptoms: An Estimation Using the Population-Based Cohorts in Japan.

    PubMed

    Yoshimura, Noriko; Nakamura, Kozo

    Although locomotive organ diseases such as osteoporotic fractures and osteoarthritis are major reasons for disability and require support, little information is available regarding the epidemiology of musculoskeletal dysfunction and its symptoms including knee pain and lumbar pain in Japan. The research on osteoarthritis/osteoporosis against disability (ROAD) study is a prospective cohort study that aims at elucidating the environmental and genetic background for locomotive organ diseases, and has been ongoing since 2005. In this review, epidemiological indices such as prevalence of locomotive organ diseases including knee osteoarthritis, lumbar spondylosis, and osteoporosis were clarified using baseline survey results of the ROAD study. The number of subjects with such diseases was estimated. In addition, 3-year follow-up data from the ROAD study revealed the effect of osteoarthritis on the occurrence of osteoporosis, and vice versa. The prevalences of osteoarthritis and osteoporosis were shown to be high. Also, the large estimates of patients with these conditions suggest that urgent strategies are needed for addressing locomotive organ diseases that cause disability in the elderly. We also clarified the prevalence of knee pain, lumbar pain, and their co-existence using the survey results of the longitudinal cohorts of motor system organ study. We found that both knee pain and lumbar pain were prevalent in 12.2 % of the total population and the presence of knee pain affected lumbar pain, and vice versa.

  16. Unicompartmental Knee Osteoarthritis (UKOA): Unicompartmental Knee Arthroplasty (UKA) or High Tibial Osteotomy (HTO)?

    PubMed Central

    Rodriguez-Merchan, E. Carlos

    2016-01-01

    The aim of this review article is to analyze the results of high tibial osteotomy compared to unicompartmental knee arthroplasty in patients with unicompartmental knee osteoarthritis. The search engine used was PubMed. The keywords were: “high tibial osteotomy versus unicompartmental knee arthroplasty”. Twenty-one articles were found on 28 February 2015, but only eighteen were selected and reviewed because they strictly focused on the topic. In a meta-analysis the ratio for an excellent outcome was higher in unicompartmental knee arthroplasty than high tibial osteotomy and the risks of revision and complications were lower in the former. A prospective comparative study showed that unicompartmental knee arthroplasty offers better long-term success (77% for unicompartmental knee arthroplasty and 60% for high tibial osteotomy at 7-10 years). However, a review of the literature showed no evidence of superior results of one treatment over the other. A multicenter study stated that unicompartmental knee osteoarthritis without constitutional deformity should be treated with unicompartmental knee arthroplasty while in cases with constitutional deformity high tibial osteotomy should be indicated. A case control study stated that unicompartmental knee arthroplasty offers a viable alternative to high tibial osteotomy if proper patient selection is done. The literature is still controversial regarding the best surgical treatment for unicompartmental knee osteoarthritis (high tibial osteotomy or unicompartmental knee arthroplasty). However, unicompartmental knee arthroplasty utilization is increasing, while high tibial osteotomy utilization is decreasing, and a meta-analysis has shown better outcomes and less risk of revision and complications in the former. A systematic review has found that with correct patient selection, both procedures show effective and reliable results. However, prospective randomized studies are needed in order to answer the question of this article

  17. Biceps tendinitis as a cause of acute painful knee after total knee arthroplasty.

    PubMed

    Pandher, Dilbans Singh; Boparai, Randhir Singh; Kapila, Rajesh

    2009-12-01

    The case report highlights an unusual case of posterolateral knee pain after total knee arthroplasty. Tendinitis of the patellar tendon or pes anserinus is a common complication after total knee arthroplasty; however, there is no report in the literature regarding the biceps femoris tendinitis causing acute pain in the early postoperative period. In this case, the biceps tendinitis was diagnosed and treated by ultrasound-guided injection into the tendon sheath.

  18. Evaluation of floating impeller phenomena in a Gyro centrifugal pump.

    PubMed

    Nishimura, Ikuya; Ichikawa, S; Mikami, M; Ishitoya, H; Motomura, T; Kawamura, M; Linneweber, J; Glueck, J; Shinohara, T; Nosé, Y

    2013-01-01

    The Gyro centrifugal pump developed as a totally implantable artificial heart was designed with a free impeller, in which the rotational shaft (male bearing) of the impeller was completely separated from the female bearing. For this type of pump, it is very important to keep the proper magnet balance (impeller-magnet and actuator-magnet) in order to prevent thrombus formation and/or bearing wear. When the magnet balance is not proper, the impeller is jerked down into the bottom bearing. On the other hand, if magnet balance is proper, the impeller lifted off the bottom of the pump housing within a certain range of pumping conditions. In this study, this floating phenomenon was investigated in detail. The floating phenomenon was proved by observation of the impeller behavior using a transparent acrylic pump. The impeller floating phenomenon was mapped on a pump performance curve. The impeller floating phenomenon is affected by the magnet-magnet coupling distance and rotational speed of the impeller. In order to keep the proper magnet balance and to maintain the impeller floating phenomenon at the driving condition of right and left pump, the magnet-magnet coupling distance was altered by a spacer which was installed between the pump and actuator. It became clear that the same pump could handle different conditions (right and left ventricular assist), by just changing the thickness of the spacer. When magnet balance is proper, the floating impeller phenomenon occurs automatically in response to the impeller rev. It is called "the dynamic RPM suspension".

  19. Is Lifelong Knee Joint Force from Work, Home, and Sport Related to Knee Osteoarthritis?

    PubMed Central

    Ratzlaff, Charles R.; Koehoorn, Mieke; Cibere, Jolanda; Kopec, Jacek A.

    2012-01-01

    Purpose. To investigate the association of cumulative lifetime knee joint force on the risk of self-reported medically-diagnosed knee osteoarthritis (OA). Methods. Exposure data on lifetime physical activity type (occupational, household, sport/recreation) and dose (frequency, intensity, duration) were collected from 4,269 Canadian men and women as part of the Physical Activity and Joint Heath cohort study. Subjects were ranked in terms of the “cumulative peak force index”, a measure of lifetime mechanical knee force. Multivariable logistic regression was conducted to obtain adjusted effects for mean lifetime knee force on the risk of knee OA. Results. High levels of total lifetime, occupational and household-related force were associated with an increased in risk of OA, with odds ratio's ranging from approximately 1.3 to 2. Joint injury, high BMI and older age were related to risk of knee OA, consistent with previous studies. Conclusions. A newly developed measure of lifetime mechanical knee force from physical activity was employed to estimate the risk of self-reported, medically-diagnosed knee OA. While there are limitations, this paper suggests that high levels of total lifetime force (all domains combined), and occupational force in men and household force in women were risk factors for knee OA. PMID:22848225

  20. A comparative evaluation of the Adaptive knee and Catech knee joints: a preliminary study.

    PubMed

    Jepson, F; Datta, D; Harris, I; Heller, B; Howitt, J; McLean, J

    2008-03-01

    The Adaptive knee joint is a microprocessor-controlled prosthetic knee that incorporates both pneumatic and hydraulic control in one electronic unit. Pneumatic control is said to provide control during swing phase and the hydraulic control during the stance phase of the gait. This hybrid controller is triggered by a computer contained within the knee that responds to input from force, time and angle sensors. The microprocessor then selects an appropriate speed and stability setting. The Catech knee joint is a conventional hydraulic knee joint. The aim of this study was to compare the Adaptive and Catech knee joints in established trans-femoral amputees. The patients meeting the inclusion criteria were all established trans-femoral amputees using the Catech knee joint. The study was carried out by performing gait analysis, assessing energy requirements using the Physiological Cost Index (PCI) and using questionnaires. There was no significant benefit gained from the use of the Adaptive knee over the Catech knee joint in our small study group.

  1. EFFECTS OF THE GENIUM MICROPROCESSOR KNEE SYSTEM ON KNEE MOMENT SYMMETRY DURING HILL WALKING

    PubMed Central

    Highsmith, M. Jason; Klenow, Tyler D.; Kahle, Jason T.; Wernke, Matthew M.; Carey, Stephanie L.; Miro, Rebecca M.; Lura, Derek J.

    2016-01-01

    Use of the Genium microprocessor knee (MPK) system reportedly improves knee kinematics during walking and other functional tasks compared to other MPK systems. This improved kinematic pattern was observed when walking on different hill conditions and at different speeds. Given the improved kinematics associated with hill walking while using the Genium, a similar improvement in the symmetry of knee kinetics is also feasible. The purpose of this study was to determine if Genium MPK use would reduce the degree of asymmetry (DoA) of peak stance knee flexion moment compared to the C-Leg MPK in transfemoral amputation (TFA) patients. This study used a randomized experimental crossover of TFA patients using Genium and C-Leg MPKs (n = 20). Biomechanical gait analysis by 3D motion tracking with floor mounted force plates of TFA patients ambulating at different speeds on 5° ramps was completed. Knee moment DoA was significantly different between MPK conditions in the slow and fast uphill as well as the slow and self-selected downhill conditions. In a sample of high-functioning TFA patients, Genium knee system accommodation and use improved knee moment symmetry in slow speed walking up and down a five degree ramp compared with C-Leg. Additionally, the Genium improved knee moment symmetry when walking downhill at comfortable speed. These results likely have application in other patients who could benefit from more consistent knee function, such as older patients and others who have slower walking speeds. PMID:28066523

  2. Improvements in knee biomechanics during walking are associated with increased physical activity after total knee arthroplasty.

    PubMed

    Arnold, John B; Mackintosh, Shylie; Olds, Timothy S; Jones, Sara; Thewlis, Dominic

    2015-12-01

    Total knee arthroplasty (TKA) in people with knee osteoarthritis increases knee-specific and general physical function, but it has not been established if there is a relationship between changes in these elements of functional ability. This study investigated changes and relationships between knee biomechanics during walking, physical activity, and use of time after TKA. Fifteen people awaiting TKA underwent 3D gait analysis before and six months after surgery. Physical activity and use of time were determined in free-living conditions from a high resolution 24-h activity recall. After surgery, participants displayed significant improvements in sagittal plane knee biomechanics and improved their physical activity profiles, standing for 105 more minutes (p=0.001) and performing 64 min more inside chores on average per day (p=0.008). Changes in sagittal plane knee range of motion (ROM) and peak knee flexion positively correlated with changes in total daily energy expenditure, time spent undertaking moderate to vigorous physical activity, inside chores and passive transport (r=0.52-0.66, p=0.005-0.047). Restoration of knee function occurs in parallel and is associated with improvements in physical activity and use of time after TKA. Increased functional knee ROM is required to support improvements in total and context specific physical activity.

  3. EFFECTS OF THE GENIUM MICROPROCESSOR KNEE SYSTEM ON KNEE MOMENT SYMMETRY DURING HILL WALKING.

    PubMed

    Highsmith, M Jason; Klenow, Tyler D; Kahle, Jason T; Wernke, Matthew M; Carey, Stephanie L; Miro, Rebecca M; Lura, Derek J

    2016-09-01

    Use of the Genium microprocessor knee (MPK) system reportedly improves knee kinematics during walking and other functional tasks compared to other MPK systems. This improved kinematic pattern was observed when walking on different hill conditions and at different speeds. Given the improved kinematics associated with hill walking while using the Genium, a similar improvement in the symmetry of knee kinetics is also feasible. The purpose of this study was to determine if Genium MPK use would reduce the degree of asymmetry (DoA) of peak stance knee flexion moment compared to the C-Leg MPK in transfemoral amputation (TFA) patients. This study used a randomized experimental crossover of TFA patients using Genium and C-Leg MPKs (n = 20). Biomechanical gait analysis by 3D motion tracking with floor mounted force plates of TFA patients ambulating at different speeds on 5° ramps was completed. Knee moment DoA was significantly different between MPK conditions in the slow and fast uphill as well as the slow and self-selected downhill conditions. In a sample of high-functioning TFA patients, Genium knee system accommodation and use improved knee moment symmetry in slow speed walking up and down a five degree ramp compared with C-Leg. Additionally, the Genium improved knee moment symmetry when walking downhill at comfortable speed. These results likely have application in other patients who could benefit from more consistent knee function, such as older patients and others who have slower walking speeds.

  4. Determination of representative dimension parameter values of Korean knee joints for knee joint implant design.

    PubMed

    Kwak, Dai Soon; Tao, Quang Bang; Todo, Mitsugu; Jeon, Insu

    2012-05-01

    Knee joint implants developed by western companies have been imported to Korea and used for Korean patients. However, many clinical problems occur in knee joints of Korean patients after total knee joint replacement owing to the geometric mismatch between the western implants and Korean knee joint structures. To solve these problems, a method to determine the representative dimension parameter values of Korean knee joints is introduced to aid in the design of knee joint implants appropriate for Korean patients. Measurements of the dimension parameters of 88 male Korean knee joint subjects were carried out. The distribution of the subjects versus each measured parameter value was investigated. The measured dimension parameter values of each parameter were grouped by suitable intervals called the "size group," and average values of the size groups were calculated. The knee joint subjects were grouped as the "patient group" based on "size group numbers" of each parameter. From the iterative calculations to decrease the errors between the average dimension parameter values of each "patient group" and the dimension parameter values of the subjects, the average dimension parameter values that give less than the error criterion were determined to be the representative dimension parameter values for designing knee joint implants for Korean patients.

  5. Effect of knee sleeve on static and dynamic balance in patients with knee osteoarthritis.

    PubMed

    Chuang, Shih-Hung; Huang, Mao-Hsiung; Chen, Tien-Wen; Weng, Ming-Chang; Liu, Chin-Wei; Chen, Chia-Hsin

    2007-08-01

    Patients with knee osteoarthritis (OA) find that use of elastic knee sleeves gives them partial pain relief and a greater sense of joint stability. However, the scientific effects of knee OA patients wearing braces are unclear. The purpose of this study was to investigate the effects of knee sleeves on static and dynamic balance in knee OA patients. Fifty patients with knee OA were enrolled in the study and all subjects were randomly divided into two groups. Initially, subjects in group A did not wear a neoprene sleeve while receiving balance tests but then wore them to be re-tested. Subjects in group B did just the reverse procedure. In this investigation, an instrument (KAT 2000; Breg Inc., Vista, CA, USA), which quantified motor control performance of the lower extremities was used and balance scores from the KAT 2000 software were obtained. The results revealed that the scores of patients wearing braces were significantly lower than those of patients without braces (p < 0.05).The finding of this study demonstrated that knee OA patients wearing knee sleeves could experience increased balance ability in both static and dynamic conditions. The improvement might prevent knee OA patients from falling down and increase their sense of security during physical activities.

  6. DIFMOS - A floating-gate electrically erasable nonvolatile semiconductor memory technology. [Dual Injector Floating-gate MOS

    NASA Technical Reports Server (NTRS)

    Gosney, W. M.

    1977-01-01

    Electrically alterable read-only memories (EAROM's) or reprogrammable read-only memories (RPROM's) can be fabricated using a single-level metal-gate p-channel MOS technology with all conventional processing steps. Given the acronym DIFMOS for dual-injector floating-gate MOS, this technology utilizes the floating-gate technique for nonvolatile storage of data. Avalanche injection of hot electrons through gate oxide from a special injector diode in each bit is used to charge the floating gates. A second injector structure included in each bit permits discharge of the floating gate by avalanche injection of holes through gate oxide. The overall design of the DIFMOS bit is dictated by the physical considerations required for each of the avalanche injector types. The end result is a circuit technology which can provide fully decoded bit-erasable EAROM-type circuits using conventional manufacturing techniques.

  7. Floating point representations in quantum circuit synthesis

    NASA Astrophysics Data System (ADS)

    Wiebe, Nathan; Kliuchnikov, Vadym

    2013-09-01

    We provide a non-deterministic quantum protocol that approximates the single qubit rotations Rx(2ϕ21ϕ22) using Rx(2ϕ1) and Rx(2ϕ2) and a constant number of Clifford and T operations. We then use this method to construct a ‘floating point’ implementation of a small rotation wherein we use the aforementioned method to construct the exponent part of the rotation and also to combine it with a mantissa. This causes the cost of the synthesis to depend more strongly on the relative (rather than absolute) precision required. We analyze the mean and variance of the T-count required to use our techniques and provide new lower bounds for the T-count for ancilla free synthesis of small single-qubit axial rotations. We further show that our techniques can use ancillas to beat these lower bounds with high probability. We also discuss the T-depth of our method and see that the vast majority of the cost of the resultant circuits can be shifted to parallel computation paths.

  8. Traumatic Floating Clavicle- A case report

    PubMed Central

    Sopu, Alexandra; Green, Connor; Molony, Diarmuid

    2015-01-01

    Introduction: Shoulder injuries after high velocity trauma are common. Clavicle is affected in almost half of these cases. Even so, bipolar dislocation of the clavicle is an unusual injury and seldom reported in the literature. Conservative management is used for almost all the cases and only selected cases will undergo surgical treatment. Case Report: A 52 year old right electrician presented to the emergency department following a fall from a push bicycle. Plain radiographs identified a left first metacarpal (MC) fracture and a bipolar fracture of his right clavicle. Following Fracture Clinic review, significant deformity of the medial clavicle was noted and a CT scan showed anterior dislocation of the medial fragment. Given the degree of deformity and this functional requirement we felt that operative treatment was most appropriate for his unstable medial clavicle fracture dislocation. Conclusion: Surgical treatment of floating clavicle has an important role in the management of fit and active patients. It is important to identify the mechanism of injury and deforming forces in fractures and only after this to plan to neutralise these where appropriate. PMID:27299032

  9. Characterization of shales using sink float procedures

    SciTech Connect

    Vadovic, C.J.

    1983-01-01

    The analysis of the organic fraction in shale leads to important processing insights. However, the analysis is complicated by the presence of a substantial fraction of rock. The rock often contains carbon, as carbonates, and hydrogen, as water of hydration, which make it extremely difficult to obtain a true organic analysis. The route used most often to obtain organic analyses is to isolate the kerogen by acid removal of the inorganics. This poses numerous problems in that the acids used, HCl and HF, can interact with and be incorporated into the organic matrix. Also basic nitrogen compounds are easily extracted from the shale. It has been observed that up to 20% of the organic carbon and up to 50% of the total nitrogen may be removed by acid extraction. To obviate these difficulties a procedure has been developed which utilizes the analyses of raw sink float shale samples to calculate the ratios of organic hydrogen and nitrogen to organic carbon. In addition an estimate of the hydrogen and nitrogen content of the mineral matter is obtained. (JMT)

  10. Characterization of shales using sink float procedures

    SciTech Connect

    Vadovic, C.J.

    1983-02-01

    The analysis of the organic fraction in shale leads to important processing insights. However, the analysis is complicated by the presence of a substantial fraction of rock. The rock often contains carbon, as carbonates, and hydrogen, as water of hydration, which make it extremely difficult to obtain a true organic analysis. The route used most often to obtain organic analyses is to isolate the kerogen by acid removal of the inorganics. This poses numerous problems in that the acids used, HCl and HF, can interact with and be incorporated into the organic matrix. Also basic nitrogen compounds are easily extracted from the shale. It has been observed that up to 20% of the organic carbon and up to 50% of the total nitrogen may be removed by acid extraction. To obviate these difficulties a procedure has been developed which utilizes the analyses of raw sink float shale samples to calculate the ratios of organic hydrogen and nitrogen to organic carbon. In addition an estimate of the hydrogen and nitrogen content of the mineral matter is obtained.

  11. Pc-Based Floating Point Imaging Workstation

    NASA Astrophysics Data System (ADS)

    Guzak, Chris J.; Pier, Richard M.; Chinn, Patty; Kim, Yongmin

    1989-07-01

    The medical, military, scientific and industrial communities have come to rely on imaging and computer graphics for solutions to many types of problems. Systems based on imaging technology are used to acquire and process images, and analyze and extract data from images that would otherwise be of little use. Images can be transformed and enhanced to reveal detail and meaning that would go undetected without imaging techniques. The success of imaging has increased the demand for faster and less expensive imaging systems and as these systems become available, more and more applications are discovered and more demands are made. From the designer's perspective the challenge to meet these demands forces him to attack the problem of imaging from a different perspective. The computing demands of imaging algorithms must be balanced against the desire for affordability and flexibility. Systems must be flexible and easy to use, ready for current applications but at the same time anticipating new, unthought of uses. Here at the University of Washington Image Processing Systems Lab (IPSL) we are focusing our attention on imaging and graphics systems that implement imaging algorithms for use in an interactive environment. We have developed a PC-based imaging workstation with the goal to provide powerful and flexible, floating point processing capabilities, along with graphics functions in an affordable package suitable for diverse environments and many applications.

  12. Multilateral installation from a floating rig

    SciTech Connect

    1998-07-01

    The Troll Olje gas province is approximately 100 km northwest of Bergen, Norway, in the Norwegian sector of the North Sea at a water depth of approximately 315 to 340 m. Troll Olje is part of the Troll gas field, where Norsk Hydro is responsible for developing two areas with thin oil rims. Before spudding the multilateral well described in this paper, 17 wells had been drilled and completed in the Troll Olje oil province. The multilateral-well concept was introduced in the gas province primarily to increase the drainage area for each well. When producing from two separate laterals, a lower drawdown pressure exists throughout the horizontal section. Therefore, gas coning is less likely to occur, and higher production rates can be sustained for a longer period of time. In addition, cost savings are substantial because of reduced well-construction time for each horizontal reservoir-drainage section and because of the reduced number of completion strings, subsea wellheads, and pipelines required for total field development. The full-length paper details design, development, testing, and installation of the first successful multilateral well installed from a floating rig offshore Norway. The paper gives a synopsis.

  13. Floating roof tank with rim space seal

    SciTech Connect

    Grove, R.B.; Peters, S.W.; Tellalian, M.L.

    1986-10-07

    This patent describes a vertical cylindrical liquid storage tank having a circular floating roof of smaller diameter than the tank thereby defining a clearance space between the roof edge and the tank wall; a seal joined to the roof and extending upwardly therefrom into slidable contact with the tank wall; the seal completely covering the clearance space; the seal comprising a plurality of individual flexible sections of sheet material in substantially side-by-side arrangement but with adjacent section side edge portions overlapping each other; a gasket between the overlapping side edge portions; a clip attached to each section adjacent its edge portion which is overlapped by the edge portion of an adjacent section; the clip having a wing spaced upward from the section to which it is attached and extending over the edge portion of the adjacent section to press the edge portions together, but permit the edge portions to slide laterally with respect to each other; and a flexible elastometric tip joined to the outer end of the sections and in slidable contact with the tank wall.

  14. Lockable Knee Brace Speeds Rehabilitation

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Marshall Space Flight Center develops key transportation and propulsion technologies for the Space Agency. The Center manages propulsion hardware and technologies of the space shuttle, develops the next generation of space transportation and propulsion systems, oversees science and hardware development for the International Space Station, manages projects and studies that will help pave the way back to the Moon, and handles a variety of associated scientific endeavors to benefit space exploration and improve life here on Earth. It is a large and diversified center, and home to a great wealth of design skill. Some of the same mechanical design skill that made its way into the plans for rocket engines and advanced propulsion at this Alabama-based NASA center also worked its way into the design of an orthotic knee joint that is changing the lives of people with weakened quadriceps.

  15. Arthroscopic lysis in knee arthrofibrosis.

    PubMed

    Vaquero, J; Vidal, C; Medina, E; Baena, J

    1993-01-01

    Arthrofibrosis continues to be a difficult complication in articular surgery on the knee. We present our experience in 21 cases of arthroscopic lysis as an alternative to mobilization under anesthesia. The technique begins with the liberation of the adhesions of the suprapatellar pouch, continues down both gutters, and ends with a cleaning of the notch where necessary. When a restriction of patellar mobility persists, we make a retinacular release. The results obtained are very satisfactory, with an average increase in the arc of mobility of 68 degrees. The average gain in mobility at 6 months is significantly greater than that achieved in the immediate postoperative period. Longer follow-up showed no improvement in range of motion after 6 months.

  16. Update management below knee intervention.

    PubMed

    Bosiers, M; Deloose, K; Verbist, J; Peeters, P

    2009-02-01

    The application of percutaneous techniques for the treatment of peripheral arterial occlusive disease (PAOD) has gained widespread interest over the last decade. Together with the development of new endovascular tools and with an increasing operator experience, the minimal invasive percutaneous therapy became first line therapy at many institutions. Patients with critical limb ischemia (CLI) due to infrapopliteal lesions are often no good candidates infra-geniculate bypass surgery (IBS), as they often present with prohibitive comorbidities, inadequate conduit, and lack of suitable distal targets for revascularization. Therefore, CLI patients due to blockage of below-the-knee (BTK) arteries are in benefit of the endovascular approach: it offers the advantages of local anesthesia, potentially reduced costs (even anticipating the need for reintervention in many patients), shorter hospital stays The current article provides an overview of the diagnosis and endovascular treatment strategies for infrapopliteal lesions in patients with CLI and gives recommendations for future infrapopliteal device technology advancements.

  17. NAVIGATION IN TOTAL KNEE ARTHROPLASTY

    PubMed Central

    da Mota e Albuquerque, Roberto Freire

    2015-01-01

    Navigation was the most significant advance in instrumentation for total knee arthroplasty over the last decade. It provides surgeons with a precision tool for carrying out surgery, with the possibility of intraoperative simulation and objective control over various anatomical and surgical parameters and references. Since the first systems, which were basically used to control the alignment of bone cutting referenced to the mechanical axis of the lower limb, many other surgical steps have been incorporated, such as component rotation, ligament balancing and arranging the symmetry of flexion and extension spaces, among others. Its efficacy as a precision tool with an effective capacity for promoting better alignment of the lower-limb axis has been widely proven in the literature, but the real value of optimized alignment and the impact of navigation on clinical results and the longevity of arthroplasty have yet to be established. PMID:27026979

  18. MRI based knee cartilage assessment

    NASA Astrophysics Data System (ADS)

    Kroon, Dirk-Jan; Kowalski, Przemyslaw; Tekieli, Wojciech; Reeuwijk, Els; Saris, Daniel; Slump, Cornelis H.

    2012-03-01

    Osteoarthritis is one of the leading causes of pain and disability worldwide and a major health problem in developed countries due to the gradually aging population. Though the symptoms are easily recognized and described by a patient, it is difficult to assess the level of damage or loss of articular cartilage quantitatively. We present a novel method for fully automated knee cartilage thickness measurement and subsequent assessment of the knee joint. First, the point correspondence between a pre-segmented training bone model is obtained with use of Shape Context based non-rigid surface registration. Then, a single Active Shape Model (ASM) is used to segment both Femur and Tibia bone. The surfaces obtained are processed to extract the Bone-Cartilage Interface (BCI) points, where the proper segmentation of cartilage begins. For this purpose, the cartilage ASM is trained with cartilage edge positions expressed in 1D coordinates at the normals in the BCI points. The whole cartilage model is then constructed from the segmentations obtained in the previous step. An absolute thickness of the segmented cartilage is measured and compared to the mean of all training datasets, giving as a result the relative thickness value. The resulting cartilage structure is visualized and related to the segmented bone. In this way the condition of the cartilage is assessed over the surface. The quality of bone and cartilage segmentation is validated and the Dice's coefficients 0.92 and 0.86 for Femur and Tibia bones and 0.45 and 0.34 for respective cartilages are obtained. The clinical diagnostic relevance of the obtained thickness mapping is being evaluated retrospectively. We hope to validate it prospectively for prediction of clinical outcome the methods require improvements in accuracy and robustness.

  19. Hyperextended Knee: Cause of Serious Injury?

    MedlinePlus

    ... www.clinicalkey.com. Accessed April 24, 2015. Brooks GP, et al. Treatment of knee injuries in the ... of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.org," "Mayo ...

  20. Is Running Bad for Your Knees?

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_162903.html Is Running Bad for Your Knees? Study suggests it may ... THURSDAY, Jan. 5, 2017 (HealthDay News) -- Everybody believes running can leave you sore and swollen, right? Well, ...

  1. Deciding to have knee or hip replacement

    MedlinePlus

    ... the hip In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; ... the knee. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; ...

  2. Risks of hip and knee replacement

    MedlinePlus

    ... the hip In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; ... the knee. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; ...

  3. Periprosthetic Knee Infection: Ten Strategies That Work

    PubMed Central

    Cavanaugh, Priscilla Ku; Diaz-Ledezma, Claudio

    2013-01-01

    Periprosthetic joint infection (PJI) is one of the most serious complications following total knee arthroplasty (TKA). The demand for TKA is rapidly increasing, resulting in a subsequent increase in infections involving knee prosthesis. Despite the existence of common management practices, the best approach for several aspects in the management of periprosthetic knee infection remains controversial. This review examines the current understanding in the management of the following aspects of PJI: preoperative risk stratification, preoperative antibiotics, preoperative skin preparation, outpatient diagnosis, assessing for infection in revision cases, improving culture utility, irrigation and debridement, one and two-stage revision, and patient prognostic information. Moreover, ten strategies for the management of periprosthetic knee infection based on available literature, and experience of the authors were reviewed. PMID:24368992

  4. American Association of Hip and Knee Surgeons

    MedlinePlus

    ... Programs Performance & Quality Practice Management FARE – AAHKS Foundation Partner With AAHKS AAHKS Committee Orientation AJRR 2016 Annual Report Hip and Knee Online Exam Page AAHKS Business Reports AAHKS Committee Orientation AAHKS News 2014 AAHKS ...

  5. Knee bone tumors: findings on conventional radiology*

    PubMed Central

    Andrade Neto, Francisco; Teixeira, Manuel Joaquim Diógenes; Araújo, Leonardo Heráclio do Carmo; Ponte, Carlos Eduardo Barbosa

    2016-01-01

    The knee is a common site for bone tumors, whether clinically painful or not. Conventional radiology has been established as the first line of investigation in patients with knee pain and can reveal lesions that often generate questions not only for the generalist physician but also for the radiologist or general orthopedist. History, image examination, and histopathological analysis compose the essential tripod of the diagnosis of bone tumors, and conventional radiology is an essential diagnostic tool in patients with knee pain. This pictorial essay proposes to depict the main conventional radiography findings of the most common bone tumors around the knee, including benign and malignant tumors, as well as pseudo-tumors. PMID:27403019

  6. Knee System Utilizing Personalized Solutions Instrumentation

    MedlinePlus

    ATTUNE® Knee System utilizing the TRUMATCH® Personalized Solutions Instrumentation Click Here to view the BroadcastMed, Inc. Privacy Policy and Legal Notice © 2017 BroadcastMed, Inc. All rights reserved.

  7. Computational Poromechanics of Human Knee Joint

    NASA Astrophysics Data System (ADS)

    Kazemi, Mojtaba; Li, LePing

    2012-02-01

    Extensive computer modeling has been performed in the recent decade to investigate the mechanical response of the healthy and repaired knee joints. Articular cartilages and menisci have been commonly modeled as single-phase elastic materials in the previous 3D simulations. A comprehensive study considering the interplay of the collagen fibers and fluid pressurization in the tissues in situ remains challenging. We have developed a 3D model of the human knee accounting for the mechanical function of collagen fibers and fluid flow in the cartilages and menisci. An anatomically accurate structure of the human knee was used for this purpose including bones, articular cartilages, menisci and ligaments. The fluid pressurization in the femoral cartilage and menisci under combined creep loading was investigated. Numerical results showed that fluid flow and pressure in the tissues played an important role in the mechanical response of the knee joint. The load transfer in the joint was clearly seen when the fluid pressure was considered.

  8. Obesity May Not Compromise Knee Surgery Success

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_164282.html Obesity May Not Compromise Knee Surgery Success Results similar ... over 35, so it's unclear if more severe obesity might increase the risk of meniscal repair failure, ...

  9. Influence of different types of low substituted hydroxypropyl cellulose on tableting, disintegration, and floating behaviour of floating drug delivery systems

    PubMed Central

    Diós, Péter; Pernecker, Tivadar; Nagy, Sándor; Pál, Szilárd; Dévay, Attila

    2014-01-01

    The object of the present study is to evaluate the effect of application of low-substituted hydroxypropyl cellulose (L-HPC) 11 and B1 as excipients promoting floating in gastroretentive tablets. Directly compressed tablets were formed based on experimental design. Face-centred central composite design was applied with two factors and 3 levels, where amount of sodium alginate (X1) and L-HPC (X2) were the numerical factors. Applied types of L-HPCs and their 1:1 mixture were included in a categorical factor (X3). Studied parameters were floating lag time, floating time, floating force, swelling behaviour of tablets and dissolution of paracetamol, which was used as a model active substance. Due to their physical character, L-HPCs had different water uptake and flowability. Lower flowability and lower water uptake was observed after 60 min at L-HPC 11 compared to L-HPC B1. Shorter floating times were detected at L-HPC 11 and L-HPC mixtures with 0.5% content of sodium alginate, whereas alginate was the only significant factor. Evaluating results of drug release and swelling studies on floating tablets revealed correlation, which can serve to help to understand the mechanism of action of L-HPCs in the field development of gastroretentive dosage forms. PMID:26702261

  10. Self-reported knee instability and activity limitations in patients with knee osteoarthritis: results of the Amsterdam osteoarthritis cohort.

    PubMed

    van der Esch, Martin; Knoop, Jesper; van der Leeden, Marike; Voorneman, Ramon; Gerritsen, Martijn; Reiding, Dick; Romviel, Suzanne; Knol, Dirk L; Lems, Willem F; Dekker, Joost; Roorda, Leo D

    2012-10-01

    The objective of this study was to evaluate whether self-reported knee instability is associated with activity limitations in patients with knee osteoarthritis (OA), in addition to knee pain and muscle strength. A cohort of 248 patients diagnosed with knee OA was examined. Self-reported knee instability was defined as the perception of any episode of buckling, shifting, or giving way of the knee in the past 3 months. Knee pain was assessed using a numeric rating scale, and knee extensor and flexor strength were measured using an isokinetic dynamometer. Activity limitations were measured by using the Western Ontario and McMasters Universities Osteoarthritis Index physical function questionnaire, the timed Get Up and Go, and the timed stair climbing and three questionnaires evaluating walking, climbing stairs, and rising from a chair. Other potential determinants of activity limitations were also collected, including joint proprioception, joint laxity, age, sex, body mass index (BMI), disease duration, and radiographic disease severity. Regression analyses evaluated the effect of adding self-reported knee instability to knee pain and muscle strength, when examining associations with the activity limitations measures. Self-reported knee instability was common (65 %) in this cohort of patients with knee OA. Analyses revealed that self-reported knee instability is significantly associated with activity limitations, even after controlling for knee pain and muscle strength. Joint proprioception, joint laxity, age, sex, BMI, duration of complaints, and radiographic severity did not confound the associations. In conclusion, self-reported knee instability is associated with activity limitations in patients with knee OA, in addition to knee pain and muscle strength. Clinically, self-reported knee instability should be assessed in addition to knee pain and muscle strength.

  11. Tantalum Cones in Revision Total Knee Arthroplasty.

    PubMed

    Kim, Eric G; Patel, Nirav K; Chughtai, Morad; Elmallah, Randa D K; Delanois, Ronald E; Harwin, Steven F; Mont, Michael A

    2016-11-01

    The best strategy to address large bony defects in revision total knee arthroplasty has yet to be determined. The relatively recent development of porous tantalum cones and their use to address massive bone loss in knee arthroplasty has shown promising short- and intermediate-term results. The purpose of this review is to present the current literature on: (1) basic science of porous tantalum, (2) classification and treatment for bone loss, (3) clinical results, and (4) evolution of newer generation cones.

  12. Multibody dynamic simulation of knee contact mechanics

    PubMed Central

    Bei, Yanhong; Fregly, Benjamin J.

    2006-01-01

    Multibody dynamic musculoskeletal models capable of predicting muscle forces and joint contact pressures simultaneously would be valuable for studying clinical issues related to knee joint degeneration and restoration. Current three-dimensional multi-body knee models are either quasi-static with deformable contact or dynamic with rigid contact. This study proposes a computationally efficient methodology for combining multibody dynamic simulation methods with a deformable contact knee model. The methodology requires preparation of the articular surface geometry, development of efficient methods to calculate distances between contact surfaces, implementation of an efficient contact solver that accounts for the unique characteristics of human joints, and specification of an application programming interface for integration with any multibody dynamic simulation environment. The current implementation accommodates natural or artificial tibiofemoral joint models, small or large strain contact models, and linear or nonlinear material models. Applications are presented for static analysis (via dynamic simulation) of a natural knee model created from MRI and CT data and dynamic simulation of an artificial knee model produced from manufacturer’s CAD data. Small and large strain natural knee static analyses required 1 min of CPU time and predicted similar contact conditions except for peak pressure, which was higher for the large strain model. Linear and nonlinear artificial knee dynamic simulations required 10 min of CPU time and predicted similar contact force and torque but different contact pressures, which were lower for the nonlinear model due to increased contact area. This methodology provides an important step toward the realization of dynamic musculoskeletal models that can predict in vivo knee joint motion and loading simultaneously. PMID:15564115

  13. Knee Instability and Basic and Advanced Function Decline in Persons with Knee Osteoarthritis

    PubMed Central

    Sharma, Leena; Chmiel, Joan S.; Almagor, Orit; Moisio, Kirsten; Chang, Alison H.; Belisle, Laura; Zhang, Yunhui; Hayes, Karen W.

    2015-01-01

    Objective Manifestations of instability in knee OA include low overall knee confidence, low confidence that the knees will not buckle, buckling, and excessive motion during gait. Confidence and buckling may particularly influence activity choices, contributing to events leading to disability. Buckling is more likely to affect advanced than basic functional tasks. In this prospective, longitudinal study, we tested the hypotheses: overall knee confidence, buckling confidence, buckling, and frontal plane motion during gait are associated with advanced 2-year function outcome in persons with knee OA. Methods Persons with knee OA were queried about overall knee confidence (higher worse), buckling confidence, and knee buckling, and underwent quantitative gait analysis to quantify varus-valgus excursion and angular velocity. Physical function was assessed using the LLFDI Basic and Advanced Lower Extremity Domain scores. Logistic regression was used to evaluate the relationship between baseline instability measures and baseline-to-2-year function outcome, adjusting for potential confounders. Results 212 persons (mean age 64.6 years, 76.9% women) comprised the sample. Buckling was significantly associated with poor advanced (adjusted OR 2.08, 95% CI: 1.03–4.20) but not basic function outcome. Overall knee confidence was significantly associated with advanced outcome (adjusted OR 1.65, 95% CI: 1.01–2.70), while associations between buckling confidence and both outcomes approached significance. Neither varus-valgus excursion nor angular velocity during gait was associated with either outcome. Conclusion Knee buckling and confidence were each associated with poor 2-year advanced function outcome. Current treatment does not address these modifiable factors; interventions to address them may improve outcome in knee OA. PMID:25732594

  14. Injury risk curves for the skeletal knee-thigh-hip complex for knee-impact loading.

    PubMed

    Rupp, Jonathan D; Flannagan, Carol A C; Kuppa, Shashi M

    2010-01-01

    Injury risk curves for the skeletal knee-thigh-hip (KTH) relate peak force applied to the anterior aspect of the flexed knee, the primary source of KTH injury in frontal motor-vehicle crashes, to the probability of skeletal KTH injury. Previous KTH injury risk curves have been developed from analyses of peak knee-impact force data from studies where knees of whole cadavers were impacted. However, these risk curves either neglect the effects of occupant gender, stature, and mass on KTH fracture force, or account for them using scaling factors derived from dimensional analysis without empirical support. A large amount of experimental data on the knee-impact forces associated with KTH fracture are now available, making it possible to estimate the effects of subject characteristics on skeletal KTH injury risk by statistically analyzing empirical data. Eleven studies were identified in the biomechanical literature in which the flexed knees of whole cadavers were impacted. From these, peak knee-impact force data and the associated subject characteristics were reanalyzed using survival analysis with a lognormal distribution. Results of this analysis indicate that the relationship between peak knee-impact force and the probability of KTH fracture is a function of age, total body mass, and whether the surface that loads the knee is rigid. Comparisons between injury risk curves for the midsize adult male and small adult female crash test dummies defined in previous studies and new risk curves for these sizes of occupants developed in this study suggest that previous injury risk curves generally overestimate the likelihood of KTH fracture at a given peak knee-impact force. Future work should focus on defining the relationships between impact force at the human knee and peak axial compressive forces measured by load cells in the crash test dummy KTH complex so that these new risk curves can be used with ATDs.

  15. Design and cadaveric validation of a novel device to quantify knee stability during total knee arthroplasty.

    PubMed

    Siston, Robert A; Maack, Thomas L; Hutter, Erin E; Beal, Matthew D; Chaudhari, Ajit M W

    2012-11-01

    The success of total knee arthroplasty depends, in part, on the ability of the surgeon to properly manage the soft tissues surrounding the joint, but an objective definition as to what constitutes acceptable postoperative joint stability does not exist. Such a definition may not exist due to lack of suitable instrumentation, as joint stability is currently assessed by visual inspection while the surgeon manipulates the joint. Having the ability to accurately and precisely measure knee stability at the time of surgery represents a key requirement in the process of objectively defining acceptable joint stability. Therefore, we created a novel sterilizable device to allow surgeons to measure varus-valgus, internal-external, or anterior-posterior stability of the knee during a total knee arthroplasty. The device can be quickly adjusted between 0 deg and 90 deg of knee flexion. The device interfaces with a custom surgical navigation system, which records the resultant rotations or translations of the knee while the surgeon applies known loads to a patient's limb with a handle instrumented with a load cell. We validated the performance of the device by having volunteers use it to apply loads to a mechanical linkage that simulated a knee joint; we then compared the joint moments calculated by our stability device against those recorded by a load cell in the simulated knee joint. Validation of the device showed low mean errors (less than 0.21 ± 1.38 Nm and 0.98 ± 3.93 N) and low RMS errors (less than 1.5 Nm and 5 N). Preliminary studies from total knee arthroplasties performed on ten cadaveric specimens also demonstrate the utility of our new device. Eventually, the use of this device may help determine how intra-operative knee stability relates to postoperative function and could lead to an objective definition of knee stability and more efficacious surgical techniques.

  16. Against Popperized epidemiology.

    PubMed

    Jacobsen, M

    1976-03-01

    The recommendation of Popper's philosophy of science should be adopted by epidemiologists is disputed. Reference is made to other authors who have shown that the most constructive elements in Popper's ideas have been advocated by earlier philosophers and have been used in epidemiology without abandoning inductive reasoning. It is argued that Popper's denigration of inductive methods is particularly harmful to epidemiology. Inductive reasoning and statistical inference play a key role in the science; it is suggested that unfamiliarity with these ideas contributes to widespread misunderstanding of the function of epidemiology. Attention is drawn to a common fallacy involving correlations between three random variables. The prevalence of the fallacy may be related to confusion between deductive and inductive logic.

  17. The epidemiology of male infertility.

    PubMed

    Winters, Brian R; Walsh, Thomas J

    2014-02-01

    The purpose of this review is to integrate understanding of epidemiology and infertility. A primer on epidemiologic science and an example disease for which the design of epidemiologic investigations is readily apparent are provided. Key features of infertility that limit epidemiologic investigation are described and a survey of available data on the epidemiology of infertility provided. Finally, the work that must be completed to move this area of research forward is proposed, and, with this new perspective of "infertility as a disease," improvements envisioned in public health that may be gained through improved understanding of the epidemiology of male infertility.

  18. Quantifying knee mechanics during balance training exercises.

    PubMed

    Benson, Lauren C; Almonroeder, Thomas G; O'Connor, Kristian M

    2017-01-01

    Patellofemoral pain (PFP) is common among runners and those recovering from anterior cruciate ligament reconstruction. Training programs designed to prevent or treat injuries often include balance training, although balance interventions have been reported to coincide with more knee injuries. Knowledge of the effect of balance exercises on knee mechanics may be useful when designing training programs. High knee abduction moment has been implicated in the development of PFP, and imbalance between vastus lateralis (VL) and vastus medialis oblique (VMO) may contribute to patellofemoral stress. The purpose was to quantify knee abduction moment and vasti muscle activity during balance exercises. Muscle activity of VMO and VL, three-dimensional lower-extremity kinematics, and ground reaction forces of healthy recreational athletes (12M, 13F) were recorded during five exercises. Peak knee abduction moment, ratio of VMO:VL activity, and delay in onset of VMO relative to VL were quantified for each exercise. The influence of sex and exercise on each variable was determined using a mixed-model ANOVA. All analyses indicated a significant main effect of exercise, p<0.05. Follow-up comparisons showed low peak knee abduction moment and high VMO:VL ratio for the task with anterior-posterior motion. Delay of VMO relative to VL was similar among balance board tasks.

  19. Arthroscopic treatment of the septic knee.

    PubMed

    Smith, M J

    1986-01-01

    Pyarthrosis of the knee was treated in 30 patients by arthroscopic decompression and lavage, coupled with parenteral and oral antibiotics. There were 21 men and nine women patients whose ages ranged from 6 months to 65 years of age. Twenty-two patients were considered to have a hematogenous origin as a cause of their pyarthrosis, and eight were caused by penetrating trauma. Twenty-eight of these patients had the onset of symptoms within 72 h prior to arthroscopy. Two adults had the onset of their symptoms 1 week prior to treatment. Follow-up has ranged from 6 months to 5 years. Staphylococcus aureus was cultured in 20 knees, Streptococcus pneumonia in three knees, Haemophilus influenzae in four knees, and Neisseria gonorrhoeae in one knee. The average hospital stay among 22 children aged 12 years or younger was 3.50 days. The other eight patients had an average hospital stay of 9.50 days. Three adults with diabetes and other medical problems, such as renal failure, had an average hospital stay of 17.33 days. Excellent results were obtained in 28 (93.3%) of 30 patients and good results were obtained in two (6.7%) of 30 patients. There were no poor results or recurrences, and no cases of osteomyelitis occurred. This method of treatment markedly reduces the morbidity and hospital stay of patients with a septic knee.

  20. Design of a reversible single precision floating point subtractor.

    PubMed

    Anantha Lakshmi, Av; Sudha, Gf

    2014-01-04

    In recent years, Reversible logic has emerged as a major area of research due to its ability to reduce the power dissipation which is the main requirement in the low power digital circuit design. It has wide applications like low power CMOS design, Nano-technology, Digital signal processing, Communication, DNA computing and Optical computing. Floating-point operations are needed very frequently in nearly all computing disciplines, and studies have shown floating-point addition/subtraction to be the most used floating-point operation. However, few designs exist on efficient reversible BCD subtractors but no work on reversible floating point subtractor. In this paper, it is proposed to present an efficient reversible single precision floating-point subtractor. The proposed design requires reversible designs of an 8-bit and a 24-bit comparator unit, an 8-bit and a 24-bit subtractor, and a normalization unit. For normalization, a 24-bit Reversible Leading Zero Detector and a 24-bit reversible shift register is implemented to shift the mantissas. To realize a reversible 1-bit comparator, in this paper, two new 3x3 reversible gates are proposed The proposed reversible 1-bit comparator is better and optimized in terms of the number of reversible gates used, the number of transistor count and the number of garbage outputs. The proposed work is analysed in terms of number of reversible gates, garbage outputs, constant inputs and quantum costs. Using these modules, an efficient design of a reversible single precision floating point subtractor is proposed. Proposed circuits have been simulated using Modelsim and synthesized using Xilinx Virtex5vlx30tff665-3. The total on-chip power consumed by the proposed 32-bit reversible floating point subtractor is 0.410 W.

  1. Rib stress fractures among rowers: definition, epidemiology, mechanisms, risk factors and effectiveness of injury prevention strategies.

    PubMed

    McDonnell, Lisa K; Hume, Patria A; Nolte, Volker

    2011-11-01

    velocity, sequential movement patterns, higher elbow-flexion to knee-extension strength ratios, higher seat-to-handle velocity during the initial drive, or higher shoulder angle excursion may result in RSF. Gearing may indirectly affect rib loading. Increased risk may be due to low calcium, low vitamin D, eating disorders, low testosterone or use of depot medroxyprogesterone injections. Injury management involves 1-2 weeks cessation of rowing with analgesic modalities followed by a slow return to rowing with low-impact intensity and modified pain-free training. Some evidence shows injury prevention strategies should focus on strengthening the serratus anterior, strengthening leg extensors, stretching the lumbar spine, increasing hip joint flexibility, reducing excessive protraction, training with ergometers on slides or floating-head ergometers, and calcium and vitamin D supplementation. Future research should focus on the epidemiology of RSF over 4-year Olympic cycles in elite rowers, the aetiology of the condition, and the effectiveness of RSF prevention strategies for injury incidence and performance in rowing.

  2. Associations of knee muscle force, bone malalignment, and knee-joint laxity with osteoarthritis in elderly people

    PubMed Central

    Nakagawa, Kazumasa; Maeda, Misako

    2017-01-01

    [Purpose] From the viewpoint of prevention of knee osteoarthritis, the aim of this study was to verify how muscle strength and joint laxity are related to knee osteoarthritis. [Subjects and Methods] The study subjects consisted of 90 community-dwelling elderly people aged more than 60 years (22 males, 68 females). Femorotibial angle alignment, knee joint laxity, knee extensors and flexor muscle strengths were measured in all subjects. In addition, the subjects were divided into four groups based on the presence of laxity and knee joint deformation, and the muscle strength values were compared. [Results] There was no significant difference in knee extensor muscle strength among the four groups. However, there was significant weakness of the knee flexor muscle in the group with deformation and laxity was compared with the group without deformation and laxity. [Conclusion] Decreased knee flexor muscle strengths may be involved in knee joint deformation. The importance of muscle strength balance was also considered. PMID:28356631

  3. Associations of knee muscle force, bone malalignment, and knee-joint laxity with osteoarthritis in elderly people.

    PubMed

    Nakagawa, Kazumasa; Maeda, Misako

    2017-03-01

    [Purpose] From the viewpoint of prevention of knee osteoarthritis, the aim of this study was to verify how muscle strength and joint laxity are related to knee osteoarthritis. [Subjects and Methods] The study subjects consisted of 90 community-dwelling elderly people aged more than 60 years (22 males, 68 females). Femorotibial angle alignment, knee joint laxity, knee extensors and flexor muscle strengths were measured in all subjects. In addition, the subjects were divided into four groups based on the presence of laxity and knee joint deformation, and the muscle strength values were compared. [Results] There was no significant difference in knee extensor muscle strength among the four groups. However, there was significant weakness of the knee flexor muscle in the group with deformation and laxity was compared with the group without deformation and laxity. [Conclusion] Decreased knee flexor muscle strengths may be involved in knee joint deformation. The importance of muscle strength balance was also considered.

  4. Nonuniform Weakness in the Paretic Knee and Compensatory Strength Gains in the Nonparetic Knee Occurs after Stroke

    PubMed Central

    Lomaglio, Melanie J.; Eng, Janice J.

    2015-01-01

    Background This study was designed to quantify torque production at different joint angles in the paretic and non-paretic knee joints of individuals with stroke. Methods Extension and flexion torques were measured at 6 angles of the knee joint and normalized to peak torque in 19 subjects with stroke and 19 controls. Results Paretic knee extension torque was lower than controls when the knee was positioned near extension. In contrast, nonparetic knee extension and flexion torques were higher than controls when the knee was positioned near full flexion. Conclusions The paretic knee extensors demonstrated exaggerated weakness at short muscle lengths and the nonparetic knee extensors and flexors demonstrated selective strength gains. Clinicians should therefore consider paretic knee extensor strengthening near full extension and promote symmetrical use of the legs to prevent compensatory overuse of the non-paretic leg. PMID:18946213

  5. Effect of center of pressure modulation on knee adduction moment in medial compartment knee osteoarthritis.

    PubMed

    Haim, Amir; Wolf, Alon; Rubin, Guy; Genis, Yulya; Khoury, Mona; Rozen, Nimrod

    2011-11-01

    The knee adduction moment (KAM) provides a major contribution to the elevated load in the medial compartment of the knee. An abnormally high KAM has been linked with the progression of knee osteoarthritis (OA). Footwear-generated biomechanical manipulations reduce the magnitude of this moment by conveying a more laterally shifted trajectory of the foot's center of pressure (COP), reducing the distance between the ground reaction force and the center of the knee joint, thus lowering the magnitude of the torque. We sought to examine the outcome of a COP shift in a cohort of female patients suffering from medial knee OA. Twenty-two female patients suffering from medial compartment knee OA underwent successive gait analysis testing and direct pedobarographic examination of the COP trajectory with a foot-worn biomechanical device allowing controlled manipulation of the COP. Modulation of the COP coronal trajectory from medial to lateral offset resulted in a significant reduction of the KAM. This trend was demonstrated in subjects with mild-to-moderate OA and in patients suffering from severe stages of the disease. Our results indicate that controlled manipulation of knee coronal kinetics in individuals suffering from medial knee OA can be facilitated by customized COP modification.

  6. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... percent for at least four hours prior to a test. (2) Mount the test material and secure it to a rigid test... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.126... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES...

  7. 49 CFR 572.176 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 70 percent for at least four hours prior to a test. (2) Mount the test material and secure it to a... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.176... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST...

  8. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the test material and secure it to a rigid test fixture as shown in Figure O5. No part of the foot or... 49 Transportation 7 2011-10-01 2011-10-01 false Knees and knee impact test procedure. 572.136... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST...

  9. 49 CFR 572.176 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 70 percent for at least four hours prior to a test. (2) Mount the test material and secure it to a... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.176... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST...

  10. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the test material and secure it to a rigid test fixture as shown in Figure O5. No part of the foot or... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.136... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST...

  11. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the test material and secure it to a rigid test fixture as shown in Figure O5. No part of the foot or... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.136... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST...

  12. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... percent for at least four hours prior to a test. (2) Mount the test material and secure it to a rigid test... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.126... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES...

  13. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... percent for at least four hours prior to a test. (2) Mount the test material and secure it to a rigid test... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.126... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES...

  14. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... percent for at least four hours prior to a test. (2) Mount the test material and secure it to a rigid test... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure. 572.126... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES...

  15. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the test material and secure it to a rigid test fixture as shown in Figure O5. No part of the foot or... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure. 572.136... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST...

  16. 49 CFR 572.176 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 70 percent for at least four hours prior to a test. (2) Mount the test material and secure it to a... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.176... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST...

  17. 49 CFR 572.136 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the test material and secure it to a rigid test fixture as shown in Figure O5. No part of the foot or... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.136... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST...

  18. 49 CFR 572.126 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... percent for at least four hours prior to a test. (2) Mount the test material and secure it to a rigid test... 49 Transportation 7 2011-10-01 2011-10-01 false Knees and knee impact test procedure. 572.126... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES...

  19. Orogenic float of the Venezuelan Andes

    NASA Astrophysics Data System (ADS)

    Monod, Bernard; Dhont, Damien; Hervouët, Yves

    2010-07-01

    The Venezuelan (or Mérida) Andes are a NE-trending intracontinental orogen that started to rise from the Middle Miocene due to the E-W far field convergence between the Maracaibo block to the northwest and the Guyana shield to the southeast. Oblique convergence is responsible for strain partitioning with thrusting along both foreland basins and right-lateral strike-slip faulting along the NE-SW Boconó fault cutting the Venezuelan Andes along-strike. The central part of the belt is also cut by the N-S left-lateral strike-slip Valera fault that connects the Boconó fault, both faults bounding the Trujillo block that escapes towards the NNE. Even though the regional geology of belt is well known, its structure at depth remains a matter of debate. Our work, based on the integration of geological and geophysical data aims to better constrain the deep geometry of faults and the tectonic evolution of the mountain belt. We used the orogenic float model to construct two NW-SE trans-Andean crustal scale balanced sections. The Late Neogene-Quaternary shortening varies from 40 km in the south to 30 km in the north across the Trujillo block, indicating that a quarter of the deformation seems to be absorbed by the tectonic escape process. More importantly, a major reorganization in the crust took place in the Early Pliocene. It is characterized by the imbrication of the Maracaibo crust into the Guyana crust. This resulted in the subduction of the Guyana lower crust and the formation of a NW-vergent basement thrust propagating upwards and surfacing along the Las Virtudes thrust. Rapid uplift of the northern flank of the belt subsequently occurred together with massive deposition of the Plio-Quaternary coarse grained Betijoque formation in the northwestern foreland basin.

  20. [Knee joint distraction: a solution for young patients with osteoarthritis of the knee?

    PubMed

    Piscaer, T M; van der Jagt, O P; Gosens, T

    2016-01-01

    The current treatment for patients with end-stage generalised osteoarthritis of the knee is total knee replacement. In a recent paper in Plos One the authors examined an alternative approach, namely knee joint distraction. On the basis of a model, they claim that this treatment can postpone total knee replacement for about 20 years. This would reduce the costs for the healthcare services and improve quality of life for these patients. Although these claims seem promising, the model is only based on extrapolations of short-term results of small cohort studies. Furthermore, concerns about potential complications, e.g. osteomyelitis following pin-tract infections, are not mentioned. Further high quality studies in knee joint distraction are needed to prove its long-term efficacy and safety before this procedure can be implemented in standard clinical care.